ANTIBIOTIC ISOXAZOLE DERIVATIVES, THEIR PRODUCTION AND USE

Abstract: The compounds of the formula: wherein R¹ is amino or an organic residue bonded through nitrogen; R² is carboxy or a group derivable therefrom; X is hydrogen, methoxy or formylamino, provided that when R¹ is acetylamino or amino and X is hydrogen, R² is not paranitrobenzyloxycarbonyl or benzhydryloxycarbonyl or salts thereof exhibit excellent antimicrobial activity, and are utilized as antimicrobial agents.

Description: This invention relates to novel 2-(4-substituted-amino-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylic acid derivatives exhibiting excellent antimicrobial and β-lactamase inhibitory activities, to processes for production thereof and to uses thereof. Recently, a novel antibiotic TAN-588 (hereinafter referred to in some instances briefly as "TAN-588") exhibiting antimicrobial activity against gram-positive and gram-negative bacteria has been harvested from new species of microorganisms belonging to the genera Empedobacter and Lysobacter as isolated from soil. The present inventors conducted research to elucidate the chemical structure of the said antibiotic TAN-588, and as a result, it has been found that the antibiotic TAN-588 has a peculiar skeleton consisting of a 3-oxoisoxazolidine ring having 5-oxo-2-tetrahydrofurancarboxylic acid bonded at its nitrogen atom [cf. Nature Vol. 325 No. 7000, pp. 179-180 (8 January, 1987)]. Heretofore, there has been reported a synthesis of a compound consisting of a 3-oxoisoxazolidine ring having a 1-methylacetic acid group introduced at its nitrogen atom [Tsuji and Yamana; Heterocycles, 8 , 153 (1977)1. However, it has been reported that the compound having the said 1-methylacetic acid group was not observed to exhibit antimicrobial activity. The present inventors synthesized derivatives of the antibiotic TAN-588 exhibiting antimicrobial activity, and as a result, it was found that the said derivatives possess excellent antimicrobial activity. The finding was followed by further research leading to this invention. The invention is concerned with: (a) a 2-((4S)-amino-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylic acid derivative of the formula (I') or a pharmaceutically acceptable salt thereof, selected from: (1) sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(methoxyimino)acetamido]-3-oxo-2-isoxasolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (2) sodium 2-{(4S)-4-[D-2-(4-ethyl-2,3-dioxo-1-piperazinocarboxamido)-2-phenylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (3) sodium 2-{(4S)-4-[D-2-(3-methylsulfonyl-2-oxoimidazolidine-1-carboxamido)-2-phenylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (4) sodium 2-{(4S)-4-[D-2-(3-furfurylidene-amino-2-oxoimidazolidine-1-carboxamido-2-phenylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (5) sodium 2-[(4S)-4-(2-thienylacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (6) sodium 2-[(4S)-4-(2-cyanoacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (7) sodium 2-{(4S)-4-[(1H)-tetrazolylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (8) sodium 2-[(4S)-4-(2-6-dimethoxybenzamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (9) sodium 2-[(4S)-4-(5-methyl-3-phenyl-2-isoxazoline -4-carboxamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (10) sodium 2-[(4S)-4-(2-ethoxynaphthalenyl-1-carboxamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (11) sodium 2-[(4S)-4-(2-cyanomethylthioacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (12) sodium 2-[(4S)-4-(2-difluoromethylthioacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (13) sodium 2-{(4S)-4-[(R)-2-(4-cyclohexyl-2,3-dioxo-1-piperazinocarboxamido-2-phenylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (14) sodium 2-((4S)-4-chloroacetamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (15) sodium 2-{(4S)-4-[2-(4-pyridylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (16) methyl 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (17) pivaloyloxymethyl 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (18) 3,5-dinitrobenzyl 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (19) p-bromophenacyl 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (20) p-bromobenzyl 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (21) sodium 2-[(4S)-4-formylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (22) sodium 2-[(4S)-4-n-butyrylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (23) sodium 2- [(4S)-4-methoxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (24) sodium 2-[(4S)-4-(N-benzyloxycarbonyl)-glycylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (25) sodium 2-[(4S)-4-benzoylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (26) sodium 2-[(4S)-4-phenylacetylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (27) sodium 2-[(4S)-4-nicotinylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (28) pivaloyloxymethyl 2-[(4S)-4-phenoxyacetylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (29) sodium 2-[(4S)-4-(p-toluenesulfonyl)amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (30) diphenylmethyl 2-[(4S)-4-(p-bromobenzoyl)-amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (31) diphenylmethyl 2-[(4S)-4(N-benzyloxy-carbonyl-D-alanyl)amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (32) 2-[(42)-4-dimethylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylic acid; (33) sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (34) sodium 2-[4-methoxy-4-(2-thienylacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (35) disodium 2-[(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(carboxymethyloxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (38) 2-{(4S)-4-[2-(2-aminomethyl)phenylacetamido]-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylic acid; (39) sodium 2-[(4S)-4-(4-fluorobenzenesulfonyl-amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (40) sodium 2-{(4S)-4-{2-[1-(2-dimethylaminoethyl)-1H-5-tetrazolylthio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (41) sodium 2-{(4S)-4-[2-(4-methyl-4H-1,2,4-triazolyl-3-ylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (42) sodium 2-{(4S)-4-[(2R,3S)-2-(4-ethyl-2,3-dioxo-1-piperazinecarboxamido)-3-formyloxybutylamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (43) disodium 2-[(4S)-4-(2-phenyl-2-sulfoacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (44) sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(E)-2-methoxyiminoacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (45) sodium 2-[(4S)-4-(2-trimethylsilyl)-ethoxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (46) sodium 2-[(4S)-4-(1-aminocyclohexylcarbonylamino)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylic acid; (47) sodium 2-{(4S)-4-[3-(2,6-dichlorophenyl)-5-methyl-4-isoxazolylcarbonylamino]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (48) sodium 2-{(4S)-4-[2-(2-pyridylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (49) sodium 2-{(4S)-4-[2-(4-pyridylmethylthio)-acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (50) sodium 2-{(4S)-4-[2-(2-pyrimidinylthio)-acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (51) sodium 2-{(4S)-4-{2-[(E)-2-(acetamidovinyl)thio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (52) sodium 2-[(4S)-4-cyclopropylcarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (53) sodium 2-[(4S)-4-methoxalylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (54) sodium 2-[(4S)-4-acrylamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (55) sodium 2-{(4S)-4-[2-(2-chloro-4-pyridyl-thio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (56) sodium 2-[(4S)-4-(2-acetamido-5-oxo-2-tetrahydrofurancarbonylamino)-3-oxo-2-isoxasolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (57) sodium 2-{(4S)-4-[2-(1-pyrazolyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (58) sodium 2-{(4S)-4-[2-(5-amino-1,2,4-thiadiazole-3-yl)-(Z)-2-ethoxyiminoacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (59) sodium 2-{(4S)-4-[2-(3-pyridazinylthio)-acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (60) sodium 2-[(4S)-4-dichloroacetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (61) sodium 2-{(4S)-4-[(2R,3S)-2-(4-ethyl-2,3-dioxo-1-piperazinecarboxamido)-3-hydroxybutyramido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (62) sodium 2-{(4S)-4-[2-(5-trifluoromethyl-1,3,4-thiadiazol-2-ylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (63) sodium 2-{(4S)-4-{2-[1-ethoxy(hydroxy)phosphinylmethyl-1H-5-tetrazolylthio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (64) sodium 2-{(4S)-4-{2-[5-(2-diethoxyphosphinylethylthio)-1,3,4-thiadiazolylthio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (65) sodium 2-{(4S)-4-[2-(1-dimethylamino-1H-5-tetrazolylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (66) sodium 2-{(4S)-4-[2-(4,5-dimethyl-2-thiazolylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (67) sodium 2-{(4S)-4-[2-(4,5-dimethyl-2-oxa-zolylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (68) sodium 2-{(4S)-4-[2-(5-methoxymethyl-1,3,4-thiadiazol-2-ylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (69) sodium 2-{(4S)-4-[2-(5-methylsulfonyl-methyl-1,3,4-thiadiazol-2-ylthio)acetamido]-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (70) sodium 2-{(4S)-4-[2-(4-ethyl-4H-1,2,4-triazol-3-ylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (71) disodium 2-{(4S)-4-[2-(5-carboxymethyl-1,3,4-thiadiazol-2-ylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (72) sodium 2-{(4S)-4-(2-[1-(2-hydroxyethyl)-1H-5-tetrazolylthio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (73) sodium 2-{(4S)-4-{2-[1-(3-dimethylamino-propyl)-1H-5-tetrazolylthio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (74) 2-[(4S)-4-(2-amino-3-sulfamoylpropionamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylic acid; (75) sodium 2-{(4S)-4-[2-(4-cyano-3-hydroxy-5-isothiazolylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (76) sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-2-oxoacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (77) sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-isopropoxyiminoacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (78) sodium 2-[(4S)-4-trifluoroacetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (79) disodium 2-{(42)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(1-carboxy-1-methylethoxyimino)acetamido]-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (80) sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(hydroxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (81) sodium 2-[(4S)-4-isobutyloxycarbonylamino-3-oxo 2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (82) diphenylmethyl 2-{(42)-4-[N-(4-nitrobenzyloxycarbonyl)glycylamino]-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (83) diphenylmethyl 2-{(4S)-4-[N-(2,2,2-trichloroethoxycarbonyl)phenylglycylamino]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (84) sodium 2-{(4S)-4-[N-(benzyloxycarbonyl)-D-phenylglycylamino]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (85) 2-[(4S)-4-L-phenylglycylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylic acid; (86) 2-{(4S)-4-D-phenylglycylamino-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylic acid; (87) sodium 2-{(4S)-4-[(2S)-(2-hydroxy-2-phenyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (88) sodium 2-{(4S)-4-[(2R)-(2-hydroxy-2-phenyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (89) sodium 2-{(4S)-4-[2-(4-chlorophenyl)-2-hydroxyacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (90) sodium 2-{(4S)-4-[2-hydroxy-2-(4-hydroxyphenyl)-acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (91) sodium 2-[(4S)-4-(2-hydroxypropionamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (92) disodium 2-[(4S)-4-(2-carboxy-2-phenylacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (93) sodium 2-[(4S)-4-benzyloxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (94) sodium 2-((4S)-4-pyruvamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (95) pivaloyloxymethyl 2-{(4S)-4-[(2R)-(2-hydroxy-2-phenyl)acetamido]-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (96) diphenylmethyl 2-[(4S)-4-(4-nitrobenzylidene)amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (97) sodium 2-{(4S)-4-[2-(3-chloro-6-pyridazinylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (98) sodium 2-[(4S)-4-(2-phenylthioacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (99) sodium 2-[(4S)-4-(2-ethoxydithiocarbonylacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (100) sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(ethoxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (101) sodium 2-{(4S)-4-[2-(2-amino-5-chloro-4-thiazolyl)-(Z)-2-(methoxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (102) sodium 2-{(42)-4-[2-4-ethyl-2,3-dioxo-1-piperazinocarboxamido)-2-thienylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (103) sodium 2-((4S)-4-ureido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (104) sodium 2-((4S)-4-phenylureylene-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (105) sodium 2-{(4S)-4-[2-(pyridyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (106) sodium 2-{(4S)-4-[2-(4-chlorophenyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (107) sodium 2-{(4S)-4-[(2-chloro-2-phenyl)acetamido]-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (108) sodium 2-{(4S)-4-[2-(3-pyridylthio)acetamido]-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (109) sodium 2-{(4S)-4-[2-(4-chlorophenylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (110) sodium 2-[(4S)-4-(2-isopropylphenoxy-carbonylamino)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (111) sodium 2-((4S)-4-difluoroacetamido-3-oxo-2-isoxazolidinyl-5-oxo-2-tetrahydrofurancarboxylate; (112) sodium 2-[(4S)-4-(3-chloro)propionamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (113) pivaloyloxymethyl 2-((4S)-4-chloroacetamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (114) pivaloyloxymethyl 2-[(4S)-4-(2-phenylthioacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (115) sodium 2-((4S)-4-propionamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (116) pivaloyloxymethyl 2-((4S)-4-benzyloxy-carbonylamino-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (117) pivaloyloxymethyl 2-((4S)-4-bromoacetamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (118) pivaloyloxymethyl 2-[(4S)-4-(2,4-hexadiene)amido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (119) pivaloyloxymethyl 2-[(4S)-4-(2-thienyl)acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (120) pivaloyloxymethyl 2-[(4S)-4-(hexahydro-1H-azepin-1-yl)methyleneamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (121) diphenylmethyl 2-[(4S)-4-(tert-butyl-dimethylsilyl)amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (122) diphenylmethyl 2-[(4S)-4-tert-butyl-diphenylsilyl)amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (123) sodium 2-[(4S)-3-diphenylphosphorylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (124) diphenylmethyl 2-[(4S)-4-dimethyl-phosphorylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (125) sodium 2-[(4S)-4-ethylsulfonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (126) sodium 2-[(4S)-4-vinylsulfonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (127) 2-[(4S)-4-thienylacetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarbonylanilide; (128) 2-[(4S)-4-benzyloxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarbonylanilide; (129) 2-[(4S)-4-benzyloxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarbonylpyrrolidinamide; (130) 2-[(4S)-4-thienylacetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarbonylpyrrolidinamide; (131) 2-[(4S)-4-thienylacetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarbonylpropylamine; (132) sodium 2-[(4S)-4-γ-D-glutamylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; and (133) sodium 2-[(4S)-4-(2-hydroxy)isobutyryl-amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (b) A pharmaceutical composition for inhibiting the growth of microorganisms which contains an effective amount of a compound (I'), or a pharmaceutically acceptable salt thereof, as defined at (a) above, together with a pharmaceutically acceptable carrier or diluent therefor. (c) A compound (I'), or a pharmaceutically acceptable salt thereof, as defined at (a) above, for use in the preparation of a pharmaceutical composition for inhibiting the growth of microorganisms. In preparing the compounds of the present invention, the antibiotic TAN-588, i.e. 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylic acid, its salts, its p-nitrobenzyl ester, its benzhydryl ester, or their N-deacetyl derivative can be employed as starting materials. The antibiotic TAN-588, which is useful as a starting compound in the processes of this invention, can be produced by cultivating an antibiotic TAN-588 producing microorganism belonging to the genus Empedobacter or Lysobacter in a culture medium to have the antibiotic TAN-588 elaborated and accumulated in the culture broth, followed by harvesting. The said producing microorganism includes, for example, the strains Empedobacter lactamgenus YK-256 and Lysobacter albus sp. nov. YK-422. The said microorganisms have been deposited at the Institution for Fermentation, Osaka (IFO, 17-85, Juso-honmachi 2-chome, Yodogawa-ku, Osaka, Japan) as described below. Microorganism IFO Accession Number Date of Deposition YK-258 IFO 14322 20th February, 1984 YK-422 IFO 14384 5th October, 1984 Also the said microorganisms have been deposited at the Fermentation Reseach Institute, Agency of Industrial Science and Technology, Ministry of International Trade and Industry, Japan, (FRI, 1-3, Yatabe-cho higashi 1-chome, Tsukuba-gun, Ibaragi Prefecture, Japan) under the accession number of FERM P-number as described below, and the deposits were converted to deposits under the Budapest Treaty and have been stored at FRI under the accession numbers of FERM BP given. Microorganism FRI Accession Number Date of Deposition Accession Number under the Budapest Treaty YK-258 FERM P-7558 26th March, 1984 FERM BP-699 YK-422 FERM P-7938 14th November, 1984 FERM BP-698 As concretly shown in the below mentioned Reference Examples, N-deacetyl derivatives of TAN-588 can be produced by introducing a p-nitrobenzyl or benzhydryl group into TAN-588 or its salt to prepare the p-nitrobenzyl ester or benzhydryl ester derivative, deacetylating the said ester derivative to prepare the p-nitrobenzyl ester or benzhydryl ester derivative of N-deacetyl TAN-588, and eliminating such ester groups. The objective compound (I') thus obtained can be isolated and purified by the per se known means, such as concentration, solvent extraction, lyophilization, crystallization, recrystallization, fractional distillation and chromatography. The presence of two asymmetric carbons in the basic skeleton allows theoretically the objective compound (I') to exist in four kinds of stereoisomers, and their individual stereoisomers and mixtures thereof fall into the scope of this invention. Similarly, the occurence of any asymmetric carbon in the groups represented by R¹ and R² results in existence of stereoisomers, and their individual stereoisomers and mixtures thereof are also included in the scope of this invention. In cases in which the above-described reaction produces these stereoisomers as a mixture, their individual stereoisomers can be isolated by the conventional methods, such as various chromatographic procedures and recrystallization, if necessary. The compound (I') of this invention can in some instances act on bases to form salts. The said base includes, for example, inorganic bases, such as sodium, potassium, lithium, calcium, magnesium and ammonia, and organic bases, such as pyridine, collidine, triethylamine and triethanolamine. The compound (I'), when produced in the free form, may beallowed to form salts by use of the conventional means, and the compound (I') obtained in the form of a salt may be converted into the free form by use of the conventional means. Also, the compound (I') in some instances forms the intramolecular salt and such a salt falls within the scope of this invention, as well. The stereoisomers of the compound (I'), either alone or as a mixture, can be used as a drug. The compound (I') thus obtained is useful as a drug, having antimicrobial activity against some species of gram-positive and gram-negative bacteria. Biological properties of the compound (I') are described in the following. Typical compounds of the compound (I') demonstrate antimicrobial spectra against different microorganisms as shown in Table 1. Test microorganism Minimum growth inhibitory concentration (µg/ml) Compound 21b 6b 1c 1b 28c R-4 Staphylococcus aureus FDA 209P 6.25 1.56 12.5 12.5 3.18 100 Escherichia coli NIHJ JC-2 25 25 1.56 3.13 >100 >100 Klebsiella pneumonae DT 50 50 0.78 1.56 100 >100 Pseudomonas aeruginosa IFO 3455 >100 >100 50 >100 >100 >100 The compound of the compound (I') of this invention wherein R¹=-NHCOH, R²=-COONa and X=H, as obtained in Example 21 (b), when administered subcutaneously to mice in the amount of 400 mg/kg, was observed to cause no lethal case. Therefore, the compound (I') or its salts are considered to be of low toxicity. As described above, the compound (I') of this invention and its salts have antimicrobial activity against some species of gram-positive and gram-negative bacteria, and in addition, are of low toxicity. Consequently, they can be used, as an antimicrobial agent or as a therapeutic agent for bacterial infections, for the treatment of bacterial infections (e.g., respiratory tract infections, urinary tract infections, suppurative diseases, bile duct infections, intratestinal infections, gynecological infections, surgical infections, etc.) in mammals (e.g., mouse, rat, dog, cattle, pig, human) being caused by infections with bacteria. The daily dosage of the compound (I') or its salt is in an amount of about 2 to 100 mg/kg as the compound (I'), more preferably about 5 to 40 mg/kg. For administration of the compound (I'), the compound (I') or its pharmacologically acceptable salt can be formulated by the conventional means with a suitable, pharmacologically acceptable carrier, excipient and diluent into such dosage form as a tablet, granule, capsule or elixir to administer orally, and also can be processed into an injectable solution by the conventional means, followed by incorporation into a sterile carrier prepared by the conventional means to administer parenterally. In producing the above-described oral pharmaceutical preparations, such as tablets, there can suitably be formulated binding agents (e.g., hydroxylpropylcellulose, hydroxypropylmethyl cellulose, macrogol, etc.), disintegrating agents (e.g., starch, carboxymethylcellulose calcium, etc.), excipients (e.g., lactose, starch, etc.), lubricants (e.g., magnesium stearate, talc, etc.) and the like. In manufacturing non-oral or parenteral pharmaceutical preparations, such as injectable solutions, there can suitably be formulated isotonizing agents (e.g., glucose, D-sorbitol, D-mannitol, sodium chloride, etc.), preservatives (e.g., benzyl alcohol, chlorobutanol, methyl p-oxybenzoate, propyl p-oxybenzoate, etc.), buffering agents (e.g., phosphate buffers, sodium acetate buffer, etc.) and the like. The Reference Example and Examples are described in the following to illustrate this invention in more detail,. The term "percent" means "weight/volume %", unless specified otherwise. In the resins to be used, the ones designated by the abbreviations are defined as follows. CHP-20: Diaion CHP-20 (produced by Mitsubishi Chemical Industries, Ltd., Japan) HP-20 : Diaion HP-20 (produced by Mitsubishi Chemical Industries, Ltd., Japan) LH-20 : Sephadex LH-20 (produced by Pharmacia Co., Sweden) XAD-2 : Amberlite XAD-2 (produced by Rohm & Haas Co., U.S.A.) SP-207: Diaion SP-207 (produced by Mitsubishi Chemical Industries, Ltd., Japan) The abbreviations used in the examples are as defined as follows. rt : Room temperature h : Hour Me : Methyl Ac : Acetyl DMA : Dimethylacetamide Reference Example 1 (1) The strain Empedobacter lactamgenus YK-258 (IFO 14322, FERM BP-699) grown on a slant of nutrient agar was inoculated into a 2-ℓ Sakaguchi flask containing 500 ml of a medium comprising an aqueous solution (pH 7.0) containing 2 % of glucose, 3 % of soluble starch, 1 % of raw soybean flour, 0.5 % of Polypepton (produced by Daigo Nutritive Chemicals, Japan) and 0.3 % of sodium chloride being admixed with 0.5 % precipitating calcium carbonate, and shake culture was carried out on a reciprocating shaker at 24°C for 48 hours. The whole volume of the resulting culture broth was inoculated into a 50-ℓ capacity tank containing 30 ℓ of the medium comprising the above medium admixed with 0.05 % of Actcol (produced by Takeda Chemical Industries, Ltd., Japan), and culture was conducted at 24°C under the conditions of aeration of 50 ℓ/min and agitation of 200 r.p.m. for 48 hours. 6 ℓ of this culture broth was inoculated into a 200-ℓ capacity tank containing 120 ℓ of a medium comprising an aqueous solution (pH 6.5) containing 3 % of dextrin, 1.5 % of raw soybean flour, 1.5 % of corn gluten meal, 0.2 % of Polypepton and 0.1 % of sodium thiosulfate being admixed with 0.05 % of Actcol, and culture was carried out at 17°C under the conditions of aeration of 200 ℓ/min and agitation of 150 r.p.m. for 66 hours. This cultivation was repeated twice, and the culture broth (230 ℓ) was adjusted to pH 8 and filtered with the use of 9kg of Hyflo Supercel (produced by Johns Manville Co. of U.S.A.). The filtrate (200 ℓ) was adjusted to pH 6 and chromatographed on a column of Amberlite IRA-402 (Cℓ type, 10 ℓ, produced by Rohm & Haas Co. of U.S.A.). The antibiotic was eluted with 2 % aqueous sodium chloride solution, and the eluate (53 ℓ) was adjusted to pH 6 and chromatographed on activated carbon (5 ℓ, produced by Takeda Chemical Industries, Ltd. of Japan). The antibiotic was eluted with 8 % aqueous isobutanol, and the eluate (14 ℓ) was concentrated under reduced pressure to 5 ℓ of the total volume. The concentrate was adjusted to pH 6, followed by extraction with 2 % tri-n-octylammonium chloride/dichloromethane solution (2.5 ℓ x 2). The extract was treated with 1.6 % aqueous sodium iodide solution (2.5 ℓ), and the antibiotic was transferred into the aqueous phase. The aqueous layer was concentrated, and the concentrate was chromatographed on activated carbon (500 ml), followed by elution with 8 % aqueous isobutanol. The eluate was concentrated and lyophilized, to give 1.41 g of a crude powder. The crude powder (1.4 g) was dissolved in water (100 ml), and the solution was chromatographed on a column of 200 ml of QAE-Sephadex A-25 (Cl type, produced by Pharmacia Co. of Sweden), followed by elution and fractionation with 0.03M aqueous sodium chloride solution. The fractions were collected (600 ml), adjusted to pH 5.1 and desalted through chromatography on activated carbon, and the eluate was concentrated and lyophilized to give a powder (384 mg). The powder was dissolved in water, and the solution was subjected to preparative HPLC using YMC-Pack SH-343 (produced by Yamamura Chemical Laboratory of Japan), followed by elution with 0.01M phosphate buffer. The eluates containing the antibiotic were collected and desalted through chromatography on activated carbon, and the eluate was concentrated and lyophilized to give a white powder (141 mg) of TAN-588 sodium salt. The TAN-588 sodium salt (an equilibrium mixture of isomers A and B) as obtained above shows physico-chemical properties as illustrated below. 1) Appearance: White powder 2) Specific rotation: [α] 23 / D -19.0° ± 10° (c=0.5, in water) 3) Elemental analysis (%) for the compound consisting of the elements, C, H, N, O and Na: for a sample dried over phosphorus pentoxide at 40°C for 6 hours. Found Calculated C, 38.5 ± 2.0 C, 39.61 H, 4.5 ± 1.0 H, 3.99 N, 9.1 ± 1.5 N, 9.24 O, 39.58 Na, 6.9 ± 1.5 Na, 7.58 4) Content of adhesive water: 3.0 ± 1.5% (by the thermogravimetric method) 5) Molecular ion peaks obtained by means of the SIMS method: m/z 611 (2M + Na)⁺, 317 (M + Na)⁺, 295 (M+ H)⁺ 6) Molecular formula: C₁₀H₁₁N₂O₇Na 7) Ultraviolet absorption (UV) spectrum (in water): 8) Infrared absorption (IR) spectrum (by the KBr tablet method): The major absorptions (wave number) as measured in KBr tablets are as follows: 3450, 1780, 1730, 1660, 1550, 1385, 1320, 1290, 1260, 1200, 1120, 1040, 980, 910, 810, 770, 690, 600, 540 cm⁻¹ 9) ¹³C-nuclear magnetic resonance (NMR) spectrum (100 MHz, in heavy water): The following signals are observed: 182.02(s), 177.30(s), 173.79(s), 173.30(s), 173.25(s), 172.58(s), 96.97(s), 96.92(s), 74.27(t), 72.63(t), 55.57(d) 55.34(d), 31.92(t), 31.08(t),30.98(t), 24.59(q) ppm (where the abbreviations denote the following: s; singlet, d; doublet, t; triplet, q; quartet). 10) Circular dichroism (CD) spectrum (in water): The negative Cotton effect is exhibited at 232 ± 3 nm. 11) Solubility: Soluble in: water, dimethylsulfoxide Sparingly soluble in: ethyl acetate, chloroform, diethyl ether. 12) Color reactions: Positive to: ninhydrin reaction Negative to: Greig-Leaback reaction, Sakaguchi reaction, Ehrlich reaction, Barton reaction and Dragendorff reaction. 13) Amino acid analysis: Hydrolysis in 6N hydrochloric acid at 105°C for 20 hours produces serine detected as the known amino acid. 14) Stability: Stable in an aqueous solution at pH 5; slightly stable at pH 3 and pH 7; unstable at pH 9. 15) Thin-layer chromatography (TLC) (cellulose f, produced by Tokyo Kasei Co. of Japan). Solvent system Rf Acetonitrile:water (4:1) 0.33 Butanol:acetic acid:water (1:1:1) 0.77 Acetonitrile:3 % ammonium sulfate (4:1) 0.28 16) Distinction between acidity, neutrality and basicity: Neutral substance. 17) High-performance liquid chromatography (HPLC) (carrier: YMC A-312, produced by Yamamura Chemical Laboratories, Japan; Mobile phase: 4 % methanol/0.01M phosphate buffer (pH 6.3), 2 ml/min.): Rt = 4.3 and 4.8 (min). (2) Using Lysobacter albus sp. nov. YK-422 (IFO 14383, FERM BP-698), cultivation and purification by a procedure similar to the above mentioned procedure produced Antibiotic TAN-588 sodium salt (620 g) a mixture of two isomers A and B). In the examples to be described in the following, the TAN-588 sodium salt (a mixture of two isomers A and B) as obtained in the above is in some instances referred to as "Compound (R-1)". Reference Example 2 In 500 ml of dichloromethane were dissolved 58.8 g of benzophenone hydrazone, 42 ml of 1,1,3,3-tetramethylguanidine and 150 mg of iodine, and after the mixed solution was cooled to 0°C to -5°C, 74 g of m-chloroperbenzoic acid (with a purity of 70 %) was added, followed by stirring at 0°C for 40 minutes. The reaction solution was washed with water and dried over sodium sulfate, and the solvent was distilled off to give diphenyldiazomethane. 31 g of TAN-588 sodium salt (a mixture of two isomers A and B) was suspended in tetrahydrofurane, and the whole amount of diphenyldiazomethane as obtained in the above was dissolved in 150 ml of tetrahydrofurane and added to the suspension. The mixed solution was cooled at 0°C, and 60 ml of 2N HCl was added dropwise, followed by stirring at room temperature for 1 hour. 10 ml of 2N HCl was added, followed by stirring for another 1 hour, and 3 ℓ of dichloromethane was added. The resulting solution was washed with water and concentrated, and ether was added to the residue to give 28 g of a white crystalline powder of TAN-588 benzhydryl ester (a mixture of isomers A and B). The above mixture (1.8 g) was chromatographed on a column of silica gel (180 ml), and elution was performed with the solvent system of chloroform:methanol (97:3), whereby the compound isomer B eluted firstly and then the compound of isomer A eluted. Each of the fractions was concentrated to give the isomer A (433 mg), isomer B (400 mg) and a mixture of the isomer A and B (476 mg) of TAN-588 benzhydryl ester in the form of colorless crystals. In the examples to be described in the following, the TAN-588 benzhydryl ester (a mixture of isomers A and B) as obtained in the above is in some instances referred to as "Compound (R-2)". The TAN-588 benzhydryl ester (a mixture of isomers A and B) as obtained in the above shows physico-chemical properties as illustrated in the following. 1) Appearance: Colorless crystals 2) Melting point: 153 to 155°C (decomposition) 3) Specific rotation: [α] 23 / D + 9.2° ± 5° (c=0.52, in CHCl₃) 4) Molecular weight: m/z, 438 (M⁺) (EI-MS method) 5) Elemental analysis: Calcd: C, 63.01; H, 5.06; N, 6.39; O, 25.54 Found: C, 62.83; H, 5.32; N, 6.28 6) Molecular formula: C₂₃H₂₂N₂O₇ 7) UV spectrum: in methanol 8) IR spectrum: KBr method 3380, 3080, 3050, 2960, 1800, 1780, 1750, 1705, 1690, 1600, 1590, 1540, 1500, 1460, 1380, 1310, 1280, 1190, 1110, 1060, 980, 920, 880, 750, 710, 700, 650, 630, 610, 570, 550, 470 cm⁻¹. 9) ¹H-NMR spectrum: 90 MHz, in CDCl₃. δ ppm J (Hz) 1.97(3H,s), 2.1-3.5(4H,m), 3.8-4.2(1H,m), 4.5-5.1(2H,m), 6.1-6.4(1H,b), 6.97(1H,s), 7.3-7.4(10H,m). (where the abbreviations denote the following: m; multiplet, b; broad, H; proton) 10) TLC: the same conditions as those to be described below, Rf value, 0.58 and 0.65 11) Distinction between acidity, neutrality and basicity: Neutral substance. The TAN-588 benzhydryl ester (isomer A) and TAN-588 benzhydryl ester (isomer B) as obtained in the above show the properties as illustrated in the following. Isomer A 1) Appearance: Colorless crystals 2) Melting point: 97-135°C (the compound undergoes gradual bubbling or foaming and decomposition). 3) Specific rotation: [α] 21 / D +44.2° ± 10° (c=0.505, in CHCl₃) 4) Molecular weight: Molecular ion peak by means of the EI-MS method. m/z 438(M⁺) 5) Elemental analysis: Calcd. C, 63.01; H, 5.06; N, 6.39; O, 25.54 Found C, 62.62; H, 5.06; N, 6.32 6) Molecular formula: C₂₃H₂₂N₂O₇ 7) UV spectrum (in methanol): 8) IR spectrum : KBr method 3380, 3080, 3050, 1800, 1780, 1760, 1685, 1540, 1500, 1450, 1380, 1310, 1280, 1190, 1110, 1050, 980, 920, 880, 750, 710, 650, 610, 550 cm⁻¹. 9) Nuclear magnetic resonance (¹H-NMR) spectrum: 100MHz, in CDCl₃-d₆-DMSO mixture, δ ppm J(Hz). 1.98(3H,s), 2.2-3.4(4H,m), 4.10(1H,dd,J=8.10), 4.4-5.0(2H,m), 6.93(1H,s), 7.3-7.5(10H,m), 8.27(1H,d,J=7) 10) Thin-layer chromatography (TLC): Carrier, silica gel (produced by Merck & Co. of West Germany). Developping solvent, ethyl acetate Rf value, 0.58 11) Distinction between acidity, neutrality and basicity: Neutral substance. Isomer B 1) Appearance: Colorless crystals 2) Melting point: 157-160°C (decomposition) 3) Specific rotation: [α] 21 / D -28.8° ± 10° (c=0.5, in CHCl₃) 4) Molecular weight: m/z 438(M⁺) (EI-MS method) 5) Elemental analysis: Calcd. C, 63.01; H, 5.06; N, 6.39; O, 25.54 Found C, 63.11; H, 5.13; N, 6.30 6) Molecular weight: C₂₃H₂₂N₂O₇ 7) UV spectrum: in methanol 8) IR spectrum: KBr method 3400, 3080, 3050, 1815, 1780, 1735, 1705, 1540, 1460, 1380, 1290, 1265, 1190, 1060, 980, 920, 880, 760, 715, 610, 550 cm⁻¹ 9) ¹H-NMR spectrum: 100 MHz, in CDCl₃, δppm J(Hz) 1.98(3H,s), 2.2-2.3(4H,m), 4.03(1H,dd,J=8,10), 4.6-5,2(2H,m), 6.32(1H,d,J=5), 6.96(1H,s), 7.2-7.5(10H,m) 10) TLC: (the same conditions as described for isomer A): Rf value, 0.65 11) Distinction between acidity, neutrality and basicity: Neutral substance. Reference Example 3 In 1.2 ℓ of dichloromethane was suspended 26 g (59 mmole) of TAN-588 benzhydryl ester (a mixture of isomers A and B), and the suspension was cooled to -20°C. 49 ml of pyridine and 37.6 g of phosphorus chloride were added to it, followed by stirring at -10° to -15°C for 50 minutes. The mixed solution was cooled to -30°C, and 180 ml of methanol was added, followed by stirring at -5° to -15°C for 30 minutes and then at room temperature for 1 hour. 100 ml of 1N HCl was added to the mixture, followed by stirring at room temperature for 45 minutes, and 100 ml of 50 % aqueous sodium phosphate and 2N sodium hydroxide (ca. 500 ml) were added to the reaction solution to adjust the pH of the aqueous layer to 8.0. The aqueous layer was separated from the dichloromethane layer and extracted with dichloroemthane (600 ml), and the organic layers were combined and concentrated, followed by addition of ether to the residue to give 17.9 g of a white powder of a benzhydryl ester of the N-deacetyl TAN-588 (a mixture of isomers A and B). In the examples to be described below, the benzhydryl ester of the N-deacetyl TAN-588 (a mixture of isomers A and B) as obtained in the above is in some instances referred to as "Compound (R-3)". The benzhydryl ester (a mixture of isomers A and B) of the N-deacetyl TAN-588 as obtained in the above shows physico-chemical properties as illustrated below. 1) Appearance: White powder 2) Specific rotation: [α] 25 / D -15.2±5° (c=0.5, in CHCl₃) 3) Molecular weight: m/z, 396(M⁺)(EI-MS method) 4) Elemental analysis: Calcd. C, 63.63; H, 5.09; N, 7.07; O, 24.22 Found C, 63.63; H, 5.05; N, 7.02 5) Molecular weight: C₂₁H₂₀N₂O₆ 6) UV spectrum: in methanol 7) IR spectrum: KBr method 3400, 3050, 2970, 1800, 1780, 1740, 1600, 1500, 1460, 1305, 1270, 1190, 1110, 1060, 980, 920, 880, 850, 750, 710, 650, 620, 605 cm⁻¹. 8) ¹H-NMR spectrum: 90 MHz, in CDCl₃ δ ppm J(Hz) 2.2-3.5(4H,m), 3.7-4.0(2H,m), 4.4-4.6(1H,m), 6.97(1H,s), 7.2-7.4(10H,m). 9) HPLC: Apparatus, Model 6000A/660/440 (Waters Assoc. of U.S.A.), Carrier, YMC-Pack A-312 (Produced by Yamamura Chemical Laboratories of Japan). Mobile phase, 65 % methanol/0.01M phosphate buffer (pH 6.3). Rate of flow, 2 ml/min, Rt, 5.3 and 5.6 min. 10) Color reactions: Positive to: Nynhydrin reaction. Negative to: Ferric chloride. 11) Distinction between acidity, neutrality and basicity: Basic substance. Reference Example 4 In 10 ml of dichloromethane was suspended 396 mg of benzhydryl ester (a mixture of isomers A and B) of the N-deacetyl TAN-588, and the suspension was cooled to -20°C. 434 µl of anisole and 924 µl of trifluoroacetic acid were added to the suspension , followed by stirring at -20° to -10°C for 40 minutes. 280 ml of dichloromethane was added to the reaction solution, followed by extraction with 0.1M H₃PO₄-Na₂HPO₄ solution (pH 7.3) (420 ml). The extract was adjusted to pH 5.5 and concentrated, and the concentrate was passed through a column packed with Diaion HP-20 (50 to 100 mesh, 100 ml). The column was washed with water, and elution was effected with 40 % aqueous methanol. The fractions exhibiting antimicrobial activity were collected, concentrated and lyophilized to give 143 mg of a white powder of the N-deacetyl TAN-588 (a mixture) of isomers A and B). The N-deacetyl TAN-588 (a mixture of isomers A and B) as obtained in the above shows physico-chemical properties as illustrated in the following. 1) Appearance: White powder. 2) Specific rotation: [a] 25 / D -11°±5° (c=0.1, in water) 3) Molecular weight: m/z, 231(M+H)⁺ (FD-MS method) 4) Elemental analysis: Found Calcd. C, 40.42 C, 40.17 H, 4.36 H, 4.64 N, 11.65 N, 11.71 O, 43.48 5) Molecular formula: C₈H₁₀N₂O₆ (0.5H₂O) 6) UV spectrum: in water 7) IR spectrum: KBr method Major peaks are as follows: 3450, 3220, 2960, 2900, 1800, 1760, 1740, 1670, 1580, 1420, 1390, 1370, 1310, 1250, 1200, 1120, 1050, 1030, 980, 950, 920, 810, 770, 720, 690, 610, 540 cm⁻¹. 8) ¹H-NMR spectrum: 400 MHz, in D₂O. The following signals are observed. δ ppm J (Hz) 2.52(1H,m), 2.27(1H,m), 2.91(1H,m), 3.08(1H,m), 4.35(1H,m), 4.56(1H,m), 4.80(1H,m). 9) Circular dichroism (CD) spectrum: in water The negative Cotton effect is exhibited at 233±3 nm. 10) Solubility: Soluble in: water Sparingly soluble in: dimethylsulfoxide, ethyl acetate, diethyl ether. 11) HPLC: The apparatus, carrier and rate of flow are as described above for the benzhydryl ester (a mixture of isomers A and B) of the N-deacetyl TAN-588. Mobile phase, 0.01M phosphate buffer (pH 6.3) Rt: 3.1 and 3.3 min. 12) Color reactions: Positive to: Nynhydrin, Iodine Negative to: Ferric chloride 13) Distinction between acidity, neutrality and basicity: Amphoteric substance. In the examples to be described below, the N-deacetyl TAN-588 (a mixture of isomers A and B) is in some instances referred to as "Compound (R-4)". Reference Example 5 In water was dissolved 100 mg of a white powder of the N-deacetyl TAN-588 (a 1:1 mixture of isomers A and B), and the solution was allowed to stand overnight at 7°C, whereby colorless crystals separated out. The crystals which separated out were recovered by filtration to give 40 mg of the N-deacetyl TAN-588 (isomer A) in the form of crystals. The crystals of the N-deacetyl TAN-588 as obtained in the above show physico-chemical properties as illustrated in the following. 1) Appearance: Colorless crystals. 2)Melting point: 177-181°C (decomposition) 3) Specific rotation: [α] 25 / D + 124° ± 20° )c=0.1, in water) 4) Molecular weight: m/z 231(M+H)⁺ (FD-MS method) 5) Elemental analysis: Found Calcd. C, 41.57 C, 41.75 H, 4.39 H, 4.38 N, 12.11 N, 12.17 O, 41.71 6) Molecualr formula: C₈H₁₀N₂O₆ 7) UV spectrum: in water 8) IR spectrum: KBr method Major absorption peaks are as follows. 3450, 3220, 2950, 2900, 1800, 1735, 1660, 1580, 1440, 1420, 1400, 1360, 1340, 1310, 1280, 1200, 1160, 1110, 1050, 1025, 980, 940, 920, 810, 770, 710, 690, 600, 540 cm⁻¹ 9) ¹H-NMR spectrum: 400 MHz, in D₂O, the following signals are observed. δppm J(Hz) 2.52(1H,m), 2.72(1H,m), 2.91(1H,m), 3.08(1H,m), 4.34(1H,m), 4.55(1H,m), 4.78(1H,m). 10) CD spectrum: in water The negative Cotton effect is exhibited at 238±3 nm. 11) Solubility: Soluble in: water Sparingly soluble in: dimethylsulfoxide, ethyl acetate, chloroform, diethyl ether. 12) HPLC: The conditions are as described above for the mixture of isomers A and B Rt, 3.3 min. 13) Distinction between acidity, neutrality and basicity: Amphoteric substance. Reference Example 6 By following the procedure of Reference Example 3, 657 mg of TAN-588 benzhydryl ester (isomer B) was reacted and treated to give 200 mg of a benzhydryl ester (isomer B) of the N-deacetyl TAN-588. 180 mg of the said compound was dissolved in 18 ml of aqueous tetrahydrofurane (1:1), and 90 mg of 10 % palladium-carbon was added to the solution, followed by stirring under a stream of hydrogen. After the catalyst was filtered out, the filtrate was concentrated, and the aqueous layer was washed with diethyl ether, concentrated and lyophilized to give 77 mg of a powder of the N-deacetyl TAN-588 (isomer B). The powder of the N-deacetyl TAN-588 as obtained in the above shows physico-chemical properties as illustrated in the following. 1) Appearance: White powder 2) Molecular weight: m/z 231 (M+H)⁺(FD-MS method) 3) Elemental analysis: Found Calcd. C, 40.98 C, 40.17 H, 4.88 H, 4.64 N, 12.17 N, 11.71 O, 43.48 4) Molecular formula: C₈H₁₀N₂O₆ 5) UV spectrum: in water 6) IR spectrum: KBr method Major peaks are as follows. 3440, 2980, 1800, 1760, 1670, 1570, 1520, 1390, 1290, 1250, 1190, 1090, 1050, 990, 920, 810, 760, 720, 690 cm⁻¹. 7) ¹H-NMR spectrum: 400MHz, in D₂O, the following signals are observed. ppm J(Hz). 2.52(1H,m), 2.72(1H,m), 2.90(1H,m), 3.08(1H,m), 4.44(1H,m), 4.68(1H,m), 4.86(1H,m). 8) CD spectrum: in water The negative Cotton effect is exhibited at 224±2 nm. 9) Solubility: Soluble in: water Sparingly soluble in: dimethylsulfoxide, ethyl acetate, chloroform, diethyl ether. 10) HPLC: The conditions are as described above for the mixture of isomers A and B. Rt, 3.1 min. 11) Distinction between acidity, neutrality and basicity: Amphoteric substance. Reference Example 7 In DMF (4 ml) was dissolved TAN-588 sodium salt (400 mg), and triethylamine (10 µl) and p-nitrobenzyl bromide (800 mg) were added to the solution, followed by stirring at room temperature for 3 hours. 0.1M phosphate buffer (pH 6.3, 50 ml) was added to the reaction solution, and extraction was effected twice with ethyl acetate (50 ml). The extract was washed with water, and concentrated, and the resultant oily material was treated with ethyl acetate-petroleum benzin to convert into powder (507 mg), thereby giving a mixture of TAN-588 p-nitrobenzyl ester (isomer A) and TAN-588 p-nitrobenzyl ester (isomer B). The resultant powder was chromatographed on a column of Sephadex LH-20 using ethyl acetate:methanol = 19:1 as a mobile phase to give TAN-588 p-nitrobenzyl ester (isomer A) (105 mg), TAN-588 p-nitrobenzyl ester (isomer B)(67 mg) and a mixture thereof (280 mg). The p-nitrobenzyl ester of TAN-588 as obtained in the above (a mixture of isomers A and B) shows physico-chemical properties as illustrated in the following. 1) Appearance: White powder. 2) Specific rotation: [α] 23 / D +16.3° ± 5° (c=0.485, in CHCl₃) 3) Molecular weight: 407 (by means of the SIMS method) 4) Elemental analysis: Calcd. C, 50.13; H, 4.21; N, 10.32; O, 35.35 Found C, 50.26; H, 4.32; N, 10.31 5) Molecular formula: C₁₇H₁₇N₃O₉ 6) UV spectrum: 7) IR spectrum: KBr method 3400, 3080, 2960, 1805, 1760, 1680, 1610, 1520, 1450, 1380, 1350, 1270, 1180, 1105, 1050, 1015, 970, 905, 850, 740, 690, 600, 540 cm⁻¹. 8) ¹H-NMR spectrum; 90MHz, in CDCl₃. δ ppm J(Hz). 2.05(3H,s), 2.3-3.3(4H,m), 4.10(1H,m), 4.5-5.1(2H,m), 5.35 (2H,s), 6.25(1H,d,like), 7.55(2H,dd,like), 8.27(2H,d,like) 9) TLC: Carrier: silica gel (produced by Merck & Co. of West Germany) Developping solvent: chloroform:methanol (19:1) Rf value, 0.25 and 0.32 10) Distinction between acidity, neutrality and basicity: Neutral substance. The TAN-588 p-nitrobenzyl ester (isomer A) as obtained in the above shows physico-chemical properties as illustrated in the following. 1) Appearance: White powder. 2) Specific rotation: [α] 20 / D +97.3°±15° (c=0.48, in CHCl₃) 3) Molecular weight: 407 (by means of the SIMS method) 4) Elemental analysis: Calcd. C, 50.13; H, 4.21; N, 10.32; O, 35.35 Found C, 50.20; H, 4.22; N, 10.13 5) Molecular formula: C₁₇H₁₇N₃O₉ 6) UV spectrum: 7) ¹³C-NMR spectrum: (100MHz, CDCl₃) 173.70(s), 171.53(s), 170.72(s), 165.09(s), 148.06(s), 141.38(s), 128.86(d), 123.91(d), 91.82(s), 71.60(t), 67.29(t), 53.00(d), 29.09(t), 27.49(t), 22.64(q) ppm. 8) IR spectrum: KBr method 3400, 3080, 2950, 1805, 1775, 1760, 1680, 1610, 1530, 1450, 1380, 1350, 1300, 1275, 1190, 1105, 1060, 1020, 980, 910, 850, 740, 700, 600, 540 cm⁻¹. 9) TLC: Carrier: silica gel (produced by Merck & Co. of West Germany) Developing solvent: chloroform:methanol (19:1) Rf value, 0.25 10) Distinction between acidity, neutrality and basicity: Neutral substance. The TAN-588 p-nitrobenzyl ester (isomer B) as obtained in the above shows physico-chemical properties as illustrated in the following. 1) Appearance: White powder 2) Specific rotation: [α] 20 / D -64.5°+15° (c=0.50, in CHCl₃) 3) Molecular weight: 407 (by means of the SIMS method) 4) Elemental analysis: Calcd. C, 50.13; H, 4.21; N, 10.32; O, 35.35 Found C, 50.10; H, 4.21; N, 10.15 5) Molecular formula: C₁₇H₁₇N₃O₉ 6) UV spectrum: 7) ¹³C-NMR spectrum: (100MHz, CDCl₃) 173.59(s), 170.86(s), 170.61(s), 165.06(s), 148.12(s), 141.24(s), 128.96(d), 123.96(d), 91.69(s), 74.60(t), 67.39(t), 51.94(d), 29.11(t), 27.38(t), 22.67(q), ppm. 8) IR spectrum: KBr method 3400, 3090, 2950, 1805, 1760, 1680, 1610, 1530, 1450, 1380, 1355, 1270, 1180, 1105, 1055, 1015, 965, 910, 855, 740, 695, 600, 540 cm⁻¹. 9) TLC: The conditions are as described above for the TAN-588 p-nitrobenzyl ester (Isomer A). Rf value, 0.32 10) Distinction between acidity, neutrality and basicity: Neutral substance. Example 1 Production of Sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(methoxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (1c)]: (a) Production of diphenylmethyl 2-{(4S)-4-[2-(2-chloroaoetamido-4-thiazolyl)-(Z)-2-(methoxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (1a)]: Diphenylmethyl 2-[(4S)-4-amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydro furancarboxylate Compound (R-3)] as obtained in Reference Example 3 was added to a solution in dimethylformamide (DMF) of 2-(2-chloroacetamido-4-thiazolyl)-(Z)-2-methoxyiminoacetic acid, 1-hydroxybenzotriazole (HOBT) and dicyclohexylcarbodiimide (DCC) under ice-cooling, followed by stirring for 1 hour. Ethyl acetate was added to the reaction solution, and the precipitate which separated out was filtered off, and the filtrate was washed with aqueous sodium hydrogencarbonate solution and water, successively, and dried over anhydrous sodium sulfate. Then, the solvent was distilled off, and the residue was chromatographed on silica gel, followed by elution with ethyl acetate-hexane (2:1) to give Compound (1a) in the form of a colorless foamed substance. (b) Production of diphenylmethyl 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(methoxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (1b)]: Compound (1a) as obtained in the above was dissolved in a mixed solution of tetrahydrofuran and water, and sodium N-methyldithiocarbamate was added little by little to the solution, followed by stirring at room temperature for 1 hour. THF was distilled off, and the residue was extracted with ethyl acetate. The extract was washed with saturated aqueous sodium chloride solution and dried over anhydrous sodium sulfate. The extract was freed of solvent, and the residue was chromatographed on silica gel, followed by elution with ethyl acetate to give Compound (1b) in the form of a colorless foamed substance. (c) Production of the subject Compound (1c): Anisole and trifluoroacetic acid were added to a dichloromethane solution of the Compound (1b) under an atmosphere of nitrogen at -10°C to -15°C, followed by stirring for 5.5 hours. The reaction solution was poured into a phosphate buffer of pH 7.0 (8 mℓ) containing sodium hydrogencarbonate (220 mg) under cooling, and the aqueous layer was separated, while the organic layer was extracted with a phosphate buffer of pH 7.0 (4 mℓ). The aqueous layers were combined, washed with dichloromethane and concentrated under reduced pressure. The concentrate was chromatographed on HP-20, and elution was performed with water, followed by lyophilization of the eluate to give the subject Compound (1c) in the form of a colorless powder. Example 2 Production of sodium 2-{(4S)-4-[D-2-(4-ethyl-2,3-dioxo-1-piperazinocarboxamido)-2-phenylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (2b)]: (a) Production of Compound (2a), a diphenylmethyl ester of the subject Compound (2b): From Compound (R-3) and N-(4-ethyl-2,3-dioxo-1-piperizinylcarbonyl)-D-phenylglycine, there was obtained Compound (2a), a diphenylmethyl ester of the subject Compound (2b), by the procedure of Example 1 (a). (b) Production of the subject Compound (2b): Compound (2a) as obtained above was dissolved in THF (10 ml) and a buffer of pH 6.86 (5 ml), and 5 % palladium-carbon (141 mg) was added to the solution followed by stirring under a hydrogen atmosphere and under ice-cooling for 20 minutes. The catalyst was filtered off, and the filtrate was freed of THF under reduced pressure. The residual solution was washed with ethyl acetate, and the aqueous layer was concentrated under reduced pressure and chromatographed on a column of XAD-2, followed by elution with 20 % aqueous ethanol. The eluate was concentrated under reduced pressure, and the concentrate was lyophilized to give the subject Compound (2b) in the form of a colorless powder. Example 3 Production of sodium 2-{(4S)-4-[D-2-(3-methylsulfonyl-2-oxoimidazolidine-1-carboxamido)-2-phenylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (3b)]: From Compound (R-3) and N-(3-methylsulfonyl-2-oxoisoxazolidinyl-1-carbonyl)-D-phenylglycine, there was obtained Compound (3a),a diphenylmethyl ester of the subject Compound (3b) by the procedure of Example 1 (a), and by following the procedure of Example 2, there was obtained the subject Compound (3b). Example 4 Production of sodium 2-{(45)-4-[D-2-(3-furfurylideneamino-2-oxoimidazolidine-1-carboxamido)-2-phenylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (4b)]: By the procedure of Example 1 (a), Compound (R-3) was acylated to give Compound (4a), a diphenylmethyl ester of the subject Compound (4b), and by the procedure of Example 2, there was obtained the subject Compound (4b). Example 5 Production of sodium 2-[(4S)-4-(2-thienylacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (5b)]: Dimethylformamide and 2-thiopheneacetyl chloride were added to a dichloromethane solution of Compound (R-3) under ice-cooling, followed by stirring for 10 minutes and then at room temperature for 20 minutes. Ethyl acetate was added to the reaction solution, and the organic layer was washed with aqueous sodium hydrogencarbonate solution and water, successively, and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and ether was added to the residue to give Compound (5a), a diphenylmethyl ester of the subject Compound (5a) in the form of a colorless powder. Then, the Compound (5a) was treated by the procedure of Example 1 (c) to give the subject Compound (5b). Example 6 Production of sodium 2-[(4S)-4-(2-cyanoacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (6b)]: Using Compound (R-3) and cyanoacetic acid, there was obtained Compound (6a), a diphenylmethyl ester of the subject Compound (6b), by the procedure of Example 1 (a), and then, the procedure of Example 2 (b) was carried out to give the subject Compound (6b). Example 7 Production of sodium 2-{[4S)-4-[(1H)-tetrazolylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (7b)]: Using Compound (R-3) and (1H)-tetrazolylacetic acid, there was obtained Compound (7a), a diphenylmethyl ester of the subject Compound (7b), by the procedure of Example 1 (a), and then the procedure of Example 2 (b) was carried out to give the subject Compound (7b). Example 8 Production of sodium 2-[(4S)-4-(2,6-dimethoxybenzamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (8b)]: Using Compound (R-3) and 2,6-dimethoxybenzoyl chloride, there was obtained Compound (8a), a diphenylmethyl ester of the subject Compound (8b), by the procedure of Example 5 and 2 (b), and then, the subject Compound (8b) was produced. Example 9 Production of sodium 2-[(4S)-4-(5-methyl-3-phenyl-2-isoxazoline-4-carboxamido)-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate [Compound (9b)]: Using Compound (R-3) and 5-methyl-3-phenyl-2-isoxazolyl-4-carbonyl chloride, there was obtained Compound (9a), a diphenylmethyl ester of the subject Compound (9b), by the procedure of Example 5, and then, the procedure of Example 2 (b) was conducted to give the subject Compound (9b). Example 10 Production of sodium 2-[(4S)-4-(2-ethoxynaphthalenyl-1-carboxamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (10b)]: Using Compound (R-3) and 2-ethoxynaphthalenyl-1-carbonyl chloride, there was obtained Compounds (10a), a diphenylmethyl ester of the subject Compound (10b), by the procedure of Example 5, and then, the procedure of Example 2 (b) was carried out to give the subject Compound (10b). Below are given the reaction conditions of Examples 1 to 10 as well as the yields and typical physico-chemical properties of the compounds obtained. Example 11 Production of sodium 2-[(4S)-4-(2-cyanomethylthioacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (11b)]: Using Compound (R-3) and cyanomethylthioacetyl chloride, there was obtained Compound (11a), a diphenylmethyl ester of the subject Compound (11b), by the procedure of Example 5, and then the procedure of Example 1 (c) was carried out to give the subject Compound (11b). Example 12 Production of sodium 2-[(4S)-4-(2-difluoromethylthioacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (12b)]: Using Compound (R-3) and difluoromethylthioacetyl chloride, there was ontained Compound (12a), a diphenylmethyl ester of the subject Compound (12b), by the procedure of Example 5, and then, the procedure of Example 1 (c) was carried out to give the subject Compound (12b). Example 13 Production of sodium 2-{(4S)-4-[(R)-2-(4-cyclohexyl-2,3-dioxo-1-piperazinocarboxamido-2-phenylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (13b)]: Using Compound (R-3) and N-(4-cyclohexyl-2,3-dioxo-1-piperazinylcarbonyl)-D-phenylglycine, there was obtained Compound (13a) (chromatography on silica gel permitted isolation of the stereoisomers in relation to the 2-position, A and B), a diphenylmethyl ester of the subject Compound (13b), by the procedure of Example 2 (a). Then, using the isomers, A and B, of Compound (13a), there was obtained the subject Compound (13b) by the procedure of Example 2 (b). Example 14 Producion of sodium 2-((4S)-4-chloroacetamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate [Compound (14b)]: Propylene oxide was added to a dichloromethane solution of Compound (R-3) under cooling at -10°C to -20°C, and then, chloroacetyl chloride was added dropwise to the mixture, followed by stirring at the same temperature for 1 hour. The reaction solution was poured into aqueous sodium hydrogencarbonate solution (10 ml), and the organic layer was separated, washed with saturated aqueous sodium chloride solution and dried over anhydrous magnesium sulfate. The solvent was distilled off, and the residue was chromatographed on a column of silica gel, followed by elution with dichloromethane:ethyl acetate: hexane (1:1:1) to give Compound (14a), a diphenylmethyl ester of the subject Compound (14b), in the form of crystals. Then, a deprotection reaction was carried out by the procedure of Example 1 (c) with Compound (14a) to give the subject Compound (14b). Example 15 Production of sodium 2-{(4S)-4-[2-(4-pyridylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (15b)]: Using Compound (14a) as obtained in Example 14, a reaction was carried out with 4-pyridinethiol to give Compound (15a), a diphenylmethyl ester of the subject Compound (15b), and the procedure of Example 1 (c) was carried out to give the subject Compound (15b). Below are given the reaction conditions of Examples 11 to 15 as well as the yields and typical physico-chemical properties of the compounds obtained. Example 16 Production of methyl 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (16)]: Sodium 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (R-1)] as obtained in Reference Example 1 was dissolved in DMF, and methyl iodide was added to the solution, followed by stirring under shield of sunlight at room temperature for 5 hours. The reaction solution was concentrated, and 50 ml of water was added to the concentrate, followed by extraction with 20 ml of dichloromethane. The extract was concentrated, and the residue was crystallized from ethyl acetate-ether to give crystals (1.36 g). The crystals (a mixture of isomers A and B, 1 g) was chromatographed on silica gel (50 g), and elution for fractionation was performed with a solvent system of chloroform-methanol (30:1). The fractions which flowed out of the column first were concentrated and crystallized to give the subject Compound (isomer B of 16), while the fraction which flowed out of the column subsequently afforded the subject Compound (isomer A of 16) in the form of a crystalline powder. Example 17 Production of pivaloyloxymethyl 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (17)]: Compound (R-1) was dissolved in DMF, and chloromethyl pivalate was added to the solution, followed by stirring . Water was added to the reaction solution, and the mixture was extracted with 150 ml of ethyl acetate. The extract was concentrated, and the resultant residue was powdered from petroleum ether. 140 mg of the resulting powder was chromatographed on Sephadex LH-20 (500 ml), and elution was performed with ethyl acetate-methanol (19:1). The corresponding fractions afforded the subject Compound (isomer B of 17) and Compound (isomer A of 17) in the form of crystals, respectively. Example 18 Production of 3,5-dinitrobenzyl 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (18)]: Compound (R-1) was dissolved in DMF, and 3,5-dinitrobenzyl chloride was added to the solution, followed by stirring. Water was added to the reaction system, and the mixture was extracted with ethyl acetate. The extract was concentrated, and the residue was powdered from petroleum ether. 624 mg of the resultant powder crystallized from acetone-hexane to give crystals of Compound (isomer A of 18). The mother liquor was also crystallized from the same solvent to give crystals of the subject Compound (isomer B of 18). Example 19 Production of p-bromophenacyl 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (19)]: Compound (R-1) was dissolved in DMF, and p-bromophenacyl bromide was added to the solution, followed by stirring. Water was added to the reaction solution, and the mixture was extracted with ethyl acetate. The extract was concentrated, and petroleum benzine was added to the residue to give 410 mg of a powder. The powder was chromatographed on Sephadex LH-20 (500 ml), and elution for fractionation was performed with a solvent system of ethyl acetate-methanol (19:1). The fraction which flowed out of the column first produced a powder of the subject Compound (isomer B of 19) and the fraction which flowed out of the column last afforded a powder of Compound (isomer A of 19), while the fraction which flowed out intermediate yielded a powder of Compound (a mixture of isomers A and B of 19). Example 20 Production of p-bromobenzyl 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (20)]: Compound (R-1) was dissolved in DMF, and triethylamine and p-bromobenzyl bromide were added to the solution, followed by stirring. 100 ml of 0.1M phosphate buffer (pH 6.3) was added to the reaction solution, and the mixture was extracted with ethyl acetate. The extract was concentrated, and chloroform and petroleum benzine were added to the residue to convert it into powder, thereby giving 562 mg of a powder. The powder was chromatographed on a column of Sephadex LH-20, and elution was performed with ethyl acetate-methanol (19:1). The fraction which flowed out of the column first yielded crystals of the subject Compound (isomer B of 20), and the fraction which flowed out last afforded crystals of Compound (isomer A of 20), while the fraction which flowed out intermediate gave a powder of Compound (a mixture of isomers A and B of 20). Below given are the reaction conditions of Examples 16 to 20 as well as the yields and typical physico-chemical properties of the compounds obtained. Example 21 Production of sodium 2-[(4S)-4-formylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (21b)]: (a) Production of diphenylmethyl 2-[(4S)-4-formylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (21a)]: Compound (R-3) was dissolved in dichloromethane, and pyridine and a mixed solution of acetic anhydride and formic acid were added to the solution, followed by stirring. The reaction solution was washed with N-hydrochloric acid and 2 % aqueous sodium hydrogencarbonate solution, successively, and the organic layer was dried and concentrated, followed by adding ether to the residue to give a powder of Compound (21a). (b) Producion of the subject Compound (21b): 10 % palladium-carbon was suspended in THF, and Compound (21a) was added to the suspension, followed by stirring under a stream of hydrogen. After the catalyst was filtered off, the filtrate was concentrated, and water was added to the concentrated residue, followed by adjustment to pH 6. The aqueous layer was washed with ether, and chromatographed on activated carbon. Elution for fractionation was performed with a solvent system of 8 % isobutanol/0.02N aqueous ammonia, and the eluate fraction was concentrated. The residue was treated with acetone and converted into powder to give a powder of the subject Compound (21b). Example 22 Production of sodium 2-[(4S)-4-n-butyrylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (22b)]: (a) Production of diphenylmethyl 2-[(4S)-4-n-butyrylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (22a)]: Compound (R-3) was dissolved in dichloromethane, and N,N-dimethylacetamide (DMA) and n-butyryl chloride were added to the solution, followed by stirring. The reaction solution was treated by the procedure of Example 21 (a) to give a powder of Compound (22a). (b) Production of the subject Compoud (22b): 10 % Palladium-carbon was suspended in THF and 0.1M phosphate buffer (pH 7.0), and Compound (22a) was added to the suspension, followed by stirring under a stream of hydrogen. After the catalyst was filtered off, the THF was distilled off, and the aqueous layer was washed with ether and chromatographed on a column of Diaion HP-20. Elution was performed with water, and the effective fraction was concentrated and lyophilized to give a powder of the subject Compound (22b). Example 23 Production of sodium 2-[(4S)-4-methoxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (23b)]: (a) Production of diphenylmethyl 2-[(4S)-4-methoxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (23a)]: Compound (R-3) was dissolved in THF, and triethylamine and methyl chlorocarbonate were added to the solution, followed by stirring. The reaction solution was treated by the procedure of Example 21 (a) to give a powder of Compound (23a). (b) Production of the subject Compound (23b): Compound (23a) was subjected to a reaction analogous to Example 22 (b), and the reaction solution was treated by the procedure of Example 21 (b) to give a powder of the subject Compound (23b). Example 24 Production of sodium 2-[(4S)-4-(N-benzyloxycarbonyl)glycylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound [24b)]: (a) Production of diphenylmethyl 2-[(4S)-4-(N-benzyloxycarbonyl)glycylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (24a)]: Methyl chlorocarbonate, N-benzyloxycarbonylglycine (Z-glycine) and triethylamine were added to THF, and a suspension of Compound (R-3) in THF was added to the said solution, followed by stirring. The reaction solution was treated by the procedure of Example 21 (a) to give crystals of Compound (24a). (b) Production of the subject Compound(24b): Compound (24a) was subjected to a reaction analogous to Example 22 (b), followed by treatment to give a powder of the subject Compound (24b). Example 25 Production of sodium 2-[(4S)-4-benzoylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (25b)]: (a) Production of diphenylmethyl 2-[(4S)-4-benzoylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (25a)]: Compound (R-3) was dissolved in dichloromethane, and DMA and benzoyl chloride were added to the solution, followed by stirring. The reaction solution was treated by the procedure of Example 21 (a) to give crystals of Compound (25a). (b) Production of the subject Compound (25b): Compound (25a) was subjected to a reaction analogous to Example 22 (b), and after treatment was conducted, the residue was chromatographed on a column of Diaion HP-20, followed by elution with 40 % aqueous methanol to give a powder of the subject Compound (25b). Example 26 Production of sodium 2-[(4S)-4-phenylacetylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (26b)]: (a) Production of diphenylmethyl 2-[(4S)-4-phenylacetylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (26b)]: Compound (R-3) was dissolved in dichloromethane, and DMA and phenylacetyl chloride were added to the solution, followed by stirring. The reaction solution was treated by the procedure of Example 21 (a) to give crystals of Compound (26a). (b) Production of the subject Compound (26b): Compound (26a) was subjected to a reaction analogous to Example 25 (b), followed by treatment to give a powder of the subject Compound (26b). Example 27 Production of sodium 2-[(4S)-4-nicotinylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (27b)]: (a) Production of diphenylmethyl 2-[(4S)-4-nicotinylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (27a)]: Compound (R-3) was dissolved in dichloromethane, and DMA and nicotinyl chloride hydrochloride were added to the solution, followed by stirring. The reaction solution was treated by the procedure of Example 21 (a) to give crystals of Compound (27a). (b) Production of the subject Compound (27b): Compound (27a) was subjected to a reaction analogous to Example 22, followed by treatment to give the subject Compound (27b) in the form of powder. Example 28 Production of pivaloyloxymethyl 2-[(4S)-4-phenoxyacetylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (28c)]: (a) Production of diphenylmethyl 2-[(4S)-4-phenoxyacetylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (28a)]: Compound (R-3) was dissolved in dichloromethane, and DMA and phenoxyacetyl chloride were added to the solution, followed by stirring. The reaction solution was treated by the procedure of Example 21 (a) to give crystals of Compound (28a). (b) Production of sodium 2-[(4S)-4-phenoxyacetylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (28b)]: Compound (28a) was subjected to a reaction analogous to Example 25 (b), followed by a work up to give a powder of the subject Compound (28b). (c) Production of the subject Compound (28c): Compound (28b) was dissolved in DMF, and chloromethyl pivalate was added to the solution, followed by stirring. Water was added to the reaction solution, and the mixture was extracted with ethyl acetate. The extract was concentrated, and hexane was added to the residue. The mixture was subjected to decantation twice and to further decantation (twice) with petroleum benzine. The residue was dried through a vacuum pump to give the subject Compound (28c). Example 29 Production of sodium 2-[(4S)-4-(p-toluenesulfonyl)amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (29b)]: (a) Production of diphenylmethyl 2-[(4S)-4-p-toluenesulfonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (29a)]: Compound (R-3) was dissolved in pyridine, and p-toluenesulfonyl chloride was added to the solution, followed by stirring. Dichloromethane and water were added to the reaction solution, and the organic layer was washed with dilute hydrochloric acid and dilute aqueous sodium hydrogencarbonate solution, successively, and concentrated. Ether was added to the concentrate to give a powder of Compound (29a). (b) Production of the subject Compound (29b): Compound (29a) was subjected to the reaction similar to Example 25 (b), followed by work up to give a powder of the subject Compound (29b). Example 30 Production of diphenylmethyl 2-[(4S)-4-(p-bromobenzoyl)amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (30a)]: Compound (R-3) was dissolved in dichloromethane, and DMA and p-bromobenzoyl chloride were added to the solution, followed by stirring. The reaction solution was subjected to a work up analogous to Example 25 (b) to give 528 mg of a crude substance of Compound (30a). This product was chromatographed on silica gel (50 g), and elution was performed with a solvent system of ethyl acetate-hexane (2:3). The eluate was concentrated to give crystals of the subject Compound (30a). Example 31 Production of diphenylmethyl 2-[(4S)-4-(N-benzyloxycarbonyl-D-alanyl)amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (31a)]: N-Benzyloxycarbonyl-D-alanine and triethylamine were added to a THF solution of methyl chlorocarbonate, and a solution of Compound (R-3) in THF was added gradually to the solution, followed by stirring. The work up was carried out according to the procedure of Example 21 (a) to give a powder of the subject Compound (31a). Below are given the reaction conditions of Examples 21 to 31 as well as the yields and typical physico-chemical properties of the compounds obtained. Example 32 Production of 2-[(4S)-4-dimethylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylic acid [Compound (32b)]: (a) Production of diphenylmethyl 2-[(4S)-4-dimethylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (32a)]: Compound (R-3) was dissolved in acetonitrile, and formaldehyde, sodium cyanoborohydride and acetic acid were added to the solution, followed by stirring. Water was added to the reaction solution, and the acetonitrile was distilled off, followed by extraction of the aqueous layer with ethyl acetate. The extract was washed with 2 % aqueous sodium hydogencarbonate solution and concentrated, and the concentrate was admixed with THF and then 2N hydrochloric acid, followed by stirring at room temperature overnight. The organic layer was concentrated, and water was added to the concentrate, followed by adjustment with aqueous dilute sodium hydroxide solution to pH 10. The water layer was extracted with ethyl acetate, and the extract was concentrated to give a powder of Compound (32a). (b) Production of the subject Compound (32b): Compound (32a) was subjected to a reaction analogous to Example 25 (b), followed by a work up to give a powder of the subject Compound (32b). Below are given the reaction conditions of Example 32 as well as the yield and typical physico-chemical properties of the compound obtained. Example 33 Production of sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (33c)]: (a) Production of diphenylmethyl 2-{(4S)-4-[2-(2-chloroacetamido-4-thiazolyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (33a)]: Using Compound (R-3) and 2-(2-chloroacetamido-4-thiazolyl)acetyl chloride, there was obtained Compound (33a) by the procedure of Example 5. (b) Production of diphenylmethyl 2-{(4S)-4-[2-(2-amino-4-thiazolyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (33b)]: The Compound (33a) as obtained above was subjected to a reaction analogous to Example 1 (b) to give Compound (33b). (c) Production of the subject Compound (33c): The Compound (33b) as obtained above was subjected to a reaction analogous to Example 1 (c) to give the subject Compound (33c). Below are given the reaction conditions of Example 33 as well as the yield and physico-chemical properties of the compound obtained. Example 34 Production of sodium 2-[4-methoxy-4-(2-thienylacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (34b)]: The Compound (5a) as obtained in Example 5 was dissolved in THF, and a methanol solution of t-butyl hypochloride and lithium methoxide was added to the solution under cooling with dry ice-acetone, followed by stirring for 5 minutes. Then, after one drop of acetic acid was added, the reaction solution was diluted with ethyl acetate, and the organic layer was washed with aqueous sodium thiosulfate solution and saturated aqueous sodium chloride solution, successively, and dried over anhydrous magnesium sulfate. The solvent was distilled off, and the residue was chromatographed on a column of silica gel to give Compound (34a), a diphenylmethyl ester of the subject Compound (349). Subsequently, the Compound (34a) was dissolved in THF, and a buffer of pH 7.0, palladium-black and palladium oxide were added to the solution, followed by stirring under a stream of hydrogen. After the catalyst was filtered off, the filtrate was concentrated under reduced pressure, and the aqueous layer was washed with ether and concentrated. The concentrate was chromatographed on a column of XAD-2, and elution was performed with 10 % ethanol. The eluate was concentrated under reduced pressure, and lyophilized to give the subject Compound (34b)in the form of a grey-white powder. Example 35 Production of disodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(carboxymethyloxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (35d)]: (a) Production of diphenylmethyl 2-{(4S)-4-[2-(2-chloroacetamido-4-thiazolyl)-(Z)-2-(4-nitrobenzyloxycarbonylmethyloxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (35a)]: Compound (R-3) was suspended in dichloromethane, and butylene oxide and 2-(2-chloroacetamido-4-thiazolyl)-(Z)-2-(4-nitrobenzyloxycarbonylmethoxyimino)acetyl chloride hydrochloride were added to the suspension under ice-cooling to allow the reaction to proceed for 1 hour. Ethyl acetate was added, and the organic layer was washed with aqueous sodium hydrogencarbonate solution and aqueous sodium chloride solution, successively, and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to give Compound (35a) in the form of a foamed substance. (b) Production of diphenylmethyl 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(4-nitrobenzyloxycarbonylmethoxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (35b)]: The Compound (35a) as obtained above was subjected to a reaction and treatment similar to those of Example 1 (b) to give Compound (35b). (c) Production of sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(4-nitrobenzyloxycarbonylmethoxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (35c)]: The Compound (35b) as obtained above was subjected to a reaction and treatment analogous to Example 1 (c) to give Compound (35c). (d) Production of the subject Compound (35d): The Compound (35c) as obtained above was subjected to a reaction and treatment analogous to Example 2 (b) to give the subject Compound (35d). Below are given the reaction conditions of Example 34 and 35 as well as the yields and typical physico-chemical properties of the compounds obtained. Example 36 Using the following ingredients, tablets are produced by the conventional means: Compound (1c) as obtained in Example 1 300 mg Corn starch 50 mg Lactose 28 mg Hydroxypropylcellulose L 20 mg Magnesium stearate 2 mg 400 mg per tablet 4 to 8 tablets are to be administered to an adult daily after each meal (three times per day). Example 37 Using the following ingredients, tablets are produced by the conventional means: Compound (35d) as obtained in Example 35 300 mg Corn starch 50 mg Lactose 28 mg Hydroxypropylcellulose L 20 mg Magnesium stearate 2 mg 400 mg per tablet 4 to 8 tablets are to be administered to an adult daily after each meal (three times per day). Example 38 Production of 2-{(4S)-4-[2-(2-aminomethyl)phenylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylic acid [Compound (38b)]: (a) Production of diphenylmethyl 2-{(4S)-4-[2-(2-benzyloxycarbonylaminomethyl)phenylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (38a)]: Using Compound (R-3) and 2-benzyloxycarbonylaminomethylphenylacetic acid, there was obtained Compound (38a) by the procedure of Example 1 (a). (b) Production of the subject Compound (38b): Compound (38a) was subjected to a reaction and treatment analogous to Example 2 (b) to give the subject Compound (38b). Example 39 Production of sodium 2-[(4S)-4-(4-fluorobenzenesulfonylamino)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (39b)]: (a) Production of diphenylmethyl 2-[(4S)-4-(4-fluorobenzenesulfonylamino)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (39a)]: Compound (R-3), 4-fluorobenzenesulfonyl chloride and propylene oxide were stirred in DMA under ice-cooling for 1 hour, followed by a treatment analogous to Example 1 (a) to give Compound (39a). b) Production of the subject Compound (39b): Compound (39a) was catalytically reduced with use of palladium black, followed by treatment by the procedure of Example 2 (b) to give the subject compound. Example 40 Production of sodium 2-{(4S)-4-{2-[1-(2-dimethylaminoethyl)-1H-5-tetrazolylthio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (40b)]: Using Compound (14a) and 1-(2-dimethylaminoethyl)-5-mercapto-1H-tetrazole, there was obtained Compound (40a), a diphenylmethyl ester of the subject Compound (40b), by the procedure of Example 15, and then, the subject Compound (40b) was formed. Example 41 Production of sodium 2-{(4S)-4-[2-(4-methyl-4H-1,2,4-triazolyl-3-ylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (41b)]: Using Compound (14a) and 3-mercapto-4-methyl-4H-1,2,4-triazole, there was obtained Compound (41a), a diphenylmethyl ester of the subject Compound (41b), by the procedure of Example 15, and then, the subject Compound (41b) was formed. Example 42 Production of sodium 2-{(4S)-4-[(2R,3S)-2-(4-ethyl-2,3-dioxo-1-piperazinecarboxamido) -3-formyloxybutylamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (42b)]: Using Compound (R-3) and (2R,3S)-2-(4-ethyl-2,3-dioxo-1-piperazinecarboxamido)-3-formyloxybutyric acid, there was obtained Compound (42a), a diphenylmethyl ester of the subject compound, by the procedure of Example 5, and then by following the procedure of Example 2(b), there was formed the subject Compound (42b). Example 43 Production of disodium 2-[(4S)-4-(2-phenyl-2-sulfoacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (43)]: Compound (R-4) as obtained in Reference Example 4 was dissolved in water, and sodium hydrogencarbonate and an ether solution of phenylsulfoacetyl chloride were added to the solution under ice-cooling with stirring. After the reaction was allowed to proceed for 1 hour, the aqueous layer was separated, washed with ethyl acetate and concentrated, and the concentrate was chromatographed on a column of XAD-2. The fraction eluted with water was lyophilized to give the subject Compound (43) in the form of a colorless powder. Example 44 Production of sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(E)-2-methoxyiminoacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (44c)]: (a) Production of diphenylmethyl 2-{(4S)-4-[2-(2-chloroacetamido-4-thiazolyl)-(E)-2-methoxyiminoacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (44a)]: Compound (R-3) and 2-(2-chloroacetamido-4-thiazolyl)-(E)-2-methoxyiminoacetic acid, there was obtained Compound (44a) by conducting a reaction and treatment analogous to Example 1 (a). (b) Production of diphenylmethyl 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(E)-2-methoxyiminoacetamido] 3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (44b)]: Using Compound (44a), there was obtained Compound (44b) by conducting a treatment by the procedure of Example 1 (b). (c) Production of the subject Compound (44c): Using Compound (44b), there was obtained the subject Compound (44c) by conducting a treatment by the procedure of Example 1 (c). Example 45 Production of sodium 2-[(4S)-4-(2-trimethylsilyl)ethoxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (45b)]: Butylene oxide and trimethylsilylethoxycarbonyl chloride were added to a dichloromethane suspension of Compound (R-3), followed by stirring for 2 hours. The solvent was distilled off, and a powder which separated out upon addition of hexane was collected by filtration to give Compound (45a), a diphenylmethyl ester of the subject compound. This product was treated by the procedure of Example 2 (b) to give the subject Compound (45b). Example 46 Production of 2-[(4S)-4-(1-aminocyclohexylcarbonylamino)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylic acid [Compound (46b)]: Using Compound (R-3) and 1-benzyloxycarbonylaminocyclohexanecarboxylic acid, a treatment was carried out by the procedure of Example 1 (a) to give diphenylmethyl 2-[(4S)-4-(1-benzyloxycarbonylaminocyclohexylcarbonylamino)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (46a)]. This product was treated by the procedure of Example 2 (b) to give the subject Compound (46b). Example 47 Production of sodium 2-{(4S)-4-[3-(2,6-dichlorophenyl)-5-methyl-4-isoxazolylcarbonylamino} -3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (47b)]: Using Compound (R-3) and 3-(2,6-dichlorophenyl)-5-methyl-4-isoxazolylcarbonyl chloride, there was obtained Compound (47a), a diphenylmethyl ester of the subject Compound (47b), by the procedure of Example 5. This product was treated by the procedure of Example 1 (c) to give the subject Compound (47b). Example 48 Production of sodium 2-{(4S)-4-[2-(2-pyridylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (48b)]: Using Compound (14a) and 2-pyridinethiol , there was obtained Compound (48a), a diphenylmethyl ester of the subject Compound (48b), by the procedure of Example 15, and then, there was formed the subject Compound (48b). Example 49 Production of sodium 2-{(4S)-4-[2-(4-pyridylmethylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (49b)]: Using Compound (14a) and 4-pyridylmethanethiol, there was obtained Compound (49a), a diphenylmethyl ester of the subject Compound (49b), by the procedure of Example 15, and then, there was formed the subject Compound (49b). Example 50 Production of sodium 2-{(4S)-4-[2-(2-pyrimidinylthio)acetamido]-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (50b)]: Using Compound (14a) and 2-pyrimidinethiol, there was obtained Compound (50a), a diphenylmethyl ester of the subject Compound (50b), by the procedure of Example 15, and then, there was formed the subject Compound (50b). Example 51 Production of sodium 2-{(4S)-4-{2-[(E)-2-(acetamidovinyl)thio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (51b)]: Using Compound (14a) and (E)-2-acetamidovinylthiol silver salt, there was obtained Compound (51a), a diphenylmethyl ester of the subject Compound (51b), by the procedure of Example 15, and then, there was formed the subject Compound (51b) Example 52 Production of sodium 2-[(4S)-4-cyclopropylcarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (52b)]: Using Compound (R-3) and cyclopropanecarboxylic acid, there was obtained Compound (52a), a diphenylmethyl ester of the subject Compound (52b), by the procedure of Example 1 (a), and then, there was formed the subject Compound (52b) by the procedure of Example 2 (b). Example 53 Production of sodium 2-[(4S)-4-methoxalylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (53b)]: Using Compound (R-3) and methyl oxalyl chloride, there was obtained Compound (53a), a dimethyl ester of the subject Compound (53b), by the procedure of Example 2(b), and then, there was formed the subject Compound (53b) by the procedure of Example 2 (b). Example 54 Production of sodium 2-[(4S)-4-acrylamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (54)]: Compound (R-3) was suspended in tetrahydrofuran, and water and 5 % palladium-carbon were added to the suspension, followed by stirring under ice-cooling and under a stream of hydrogen. After the catalyst was filtered off, the filtrate was washed with water, and the filtrate and washings were combined and concentrated under reduced pressure. The concentrate was washed with ethyl acetate, and the aqueous layer was separated out and admixed, under ice-cooling with stirring, with sodium hydrogencarbonate and a tetrahydrofuran solution of acryloyl chloride. The reaction solution was washed with ethyl acetate, and the aqueous layer was concentrated. The concentrate was chromatographed on a column of HP-20, and the fraction eluted with water was lyophilized to give the subject Compound (54). Example 55 Production of sodium 2-{(4S)-4-[2-(2-chloro-4-pyridylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (55b)]: Using Compound (14a) and 2-chloro-4-pyridinethiol, there was obtained Compound (55a), a diphenylmethyl ester of the subject Compound (55b), by the procedure of Example 15, and then, there was formed the subject Compound (55b). Example 56 Production of sodium 2-[(4S)-4-(2-acetamido-5-oxo-2-tetrahydrofurancarbonylamino)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (56b)]: Using Compound (R-3) and 2-acetamido-5-oxo-2-tetrahydrofurancarboxylate, there was obtained Compound (56a), a diphenylmethyl ester of the subject Compound (56b), by the procedure of Example 1 (a), and then, there was formed the subject Compound (56b) by the procedure of Example 2 (b). Example 57 Production of sodium 2-{(4S)-4-[2-(1-pyrazolyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (57b)]: Using Compound (R-3) and 1-pyrazolylacetic acid, there was obtained Compound (57a), a diphenylmethyl ester of the subject Compound (57b), by the procedure of Example 1 (a), and then, there was formed the subject Compound (57b) by the procedure of Example 2 (b). Example 58 Production of sodium 2-{(4S)-4-[2-(5-amino-1,2,4-thiadiazole-3-yl)-(Z)-2-ethoxyiminoacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (58b)]: Using Compound (R-3) and 2-(5-amino-1,2,4-thidiazole-3-yl)-(Z)-2-ethoxyiminoacetic acid, there was obtained Compound (58a), a diphenylmethyl ester of the subject Compound (58b), by the procedure of Example 1 (a), and then, there was formed the subject Compound (58b)by the procedure of Example 1 (c). Example 59 Production of sodium 2-{(4S)-4-[2-(3-pyridazinylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (59b)]: Using Compound (14a) and 3-pyridazinethiol lithium salt, there was obtained Compound (59a), a diphenylmethyl ester of the subject Compound (59b), by the procedure of Example 15, and then, there was formed the subject Compound (59b). Example 60 Production of sodium 2-[(4S)-4-dichloroacetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (60b)]: Using Compound (R-3) and dichloroacetyl chloride, there was obtained Compound (60a), a diphenylmethyl ester of the subject Compound (60b), by the procedure of Example 14, and then, there was formed the subject Compound (60b). Example 61 Production of sodium 2-{(4S)-4-[(2R,3S)-2-(4-ethyl-2,3-dioxo-1-piperazinecarboxamido)-3-hydroxybutyramido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (61b)]: Using Compound (R-3) and (2R,3S)-2-(4-ethyl-2,3-dioxo-1-piperazinecarboxamido)-3-hydroxybutyric acid, there was obtained Compound (61a), a diphenylmethyl ester of the subject Compound (61b), through a reaction analogous to Example 1 (a), and there was formed the subject Compound (61b) through catalytic reduction with use of palladium black. Example 62 Production of sodium 2-{(4S)-4-[2-(5-trifluoromethyl}-1,3,4-thiadiazol -2-ylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (62b)]: Using Compound 14 (a) and 5-trifluoromethyl-1,3,4-thiadiazole-2-thiol, there was obtained Compound (62a), a diphenylmethyl ester of the subject Compound (62b), by the procedure of Example 15, and then, there was formed the subject Compound (62b). Example 63 Production of disodium 2-{(4S)-4-{2-[1-ethoxy(hydroxy)phosphinylmethyl-1H-5-tetrazolylthio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (63b)]: Using Compound (14a) and 1-[ethoxy(hydroxy)phosphinylmethyl]-1H-tetrazole-5-thiol O,S-disodium salt, there was obtained Compound (63a), a diphenylmethyl ester of the subject Compound (63b), by the procedure of Example 15, and then, there was formed the subject Compound (63b). Example 64 Production of sodium 2-{(4S)-4-{2-[5-(2-diethoxyphosphinylethylthio)-1,3,4-thiadiazolylthio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (64b)]: Using Compound (14a) and 5-(2-diethoxyphosphinylethylthio)-1,3,4-thiadiazole-2-thiol, there was obtained Compound (64a), a diphenylmethyl ester of the subject Compound (64b), by the procedure of Example 15, and then, there was formed the subject Compound (64b). Example 65 Production of sodium 2-{(4S)-4-[2-(1-dimethylamino-1H-5-tetrazolylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (65b)]: Using Compound (14a) and 1-dimethylamino-1H-tetrazole-5-thiol, there was obtained Compound (65a), a diphenylmethyl ester of the subject Compound (65b), by the procedure of Example 15, and then, there was formed the subject Compound (65b). Example 66 Production of sodium 2-{(4S)-4-[2-(4,5-dimethyl-2-thiazolylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (66b)]; Using Compound 14 (a) and 4,5-dimethyl-2-thiazolethiol, there was obtained Compound (66a), a diphenylmethyl ester of the subject Compound (66b), by the procedure of Example 15, and then, there was formed the subject Compound (66b). Example 67 Production of sodium 2-{(4S)-4-[2-(4,5-dimethyl-2-oxazolylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (67b)]: Using Compound (14a) and 4,5-dimethyl-2-oxazolethiol, there was obtained Compound (67a), a diphenylmethyl ester of the subject Compound (67b), by the procedure of Example 15, and then, there was formed the subject Compound (67b). Example 68 Production of sodium 2-{(4S)-4-[2-(5-methoxymethyl-1,3,4-thiadiazol-2-ylthio)acetamido]-3-oxo-2-isoxazolydinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound 68b)[: Using Compound (14a) and 5-methoxymethyl-1,3,4-thiadiazole-2-thiol, there was obtained Compound (68a), a diphenylmethyl ester of the subject Compound (68b), by the procedure of Example 15, and then, there was formed the subject Compound (68b). Example 69 Production of sodium 2-{(4S)-4-[2-(5-methylsulfonylmethyl-1,3,4-thiadiazol -2-ylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (69b)]: Using Compound (14a) and 5-methylsulfonylmethyl-1,3,4-thiadiazole-2-thiol, there was obtained Compound (69a), a diphenylmethyl ester of the subject Compound (69a), by the procedure of Example 15, and then, there was formed the subject Compound (69b). Example 70 Production of sodium 2-{(4S)-4-[2-(4-ethyl-4H-1,2,4-triazol-3-ylthio)acetamido]-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate [Compound (70b)]: Using Compound (14a) and 4-ethyl-4H-1,2,4-triazole-3-thiol, there was obtained Compound (70a), a diphenylmethyl ester of the subject Compound (70b), by the procedure of Example 15, and then, there was formed the subject Compound (70b). Example 71 Production of disodium 2-{(4S)-4-[2-(5-carboxymethyl-1,3,4-thiadiazol -2-ylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (71b)]: Using Compound (14a) and sodium 2-mercapto-1,3,4-thiadiazol -5-ylacetate, there was obtained Compound (71a], a diphenylmethyl ester of the subject Compound (71b), by the procedure of Example 15, and then, there was formed the subject Compound (71b). Example 72 Production of sodium 2-{(4S)-4-{2-[1-(2-hydroxyethyl)-1H-5-tetrazolylthio]acetamido}-3-oxo-2-isoxazolidinyl-5-oxo-2-tetrahydrofurancarboxylate [Compound (72b)]: Using Compound(14a) and 1-(2-hydroxyethyl)-1H-tetrazole-5-thiol, there was obtained Compound (72a), a diphenylmethyl ester of the subject Compound (72b), by a the procedure of Example 15, and then, there was formed the subject Compound (72b). Example 73 Production of sodium 2-{(4S)-4-{2-[1-(3-dimethylaminopropyl)-1H-5-tetrazolylthio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (73b)]: Using Compound (14a) and 1-(3-dimethylaminopropyl)-1H-tetrazole-5-thiol, there was obtained Compound (73a), a diphenylmethyl ester of the subject Compound (73b), by the procedure of Example 15, and then, there was formed the subject Compound (73b). Example 74 Production of 2-[(4S)-4-(2-amino-3-sulfamoylpropionamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylic acid [Compound (74b)]: Using Compound (R-3) and 2-benzyloxycarbonylamino-3-sulfamoylpropionic acid, there was obtained Compound (74a), a diphenylmethyl ester of the subject Compound (74b), through a reaction analogous to Example 1 (a), and then, there was formed the subject Compound (74b) through catalytic reduction with use of palladium-balck as a catalyst. Example 75 Production of sodium 2-{(4S)-4-[2-(4-cyano-3-hydroxy-5-isothiazolylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (75b)]: Using Compound (R-3) and 4-cyano-3-hydroxy-5-isothiazolylacetic acid, there was obtained Compound (75a), a diphenylmethyl ester of the subject Compound (75b), through a reaction analogous to Example 1 (a), and then there was obtained the subject Compound (75b). Example 76 Produciton of sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-2-oxoacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-terahydrofurancarboxylate [Compound (76c)]: Using Compound (R-3) and 2-(2-chloroacetamido-4-thiazolyl)-2-oxoacetic acid, there was obtained diphenylmethyl (4S)-2-{4-[2-(2-chloroacetamido-4-thiazolyl)-2-oxoacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (76a)] through a reaction analogous to Example 1, and after this product was converted into Compound (76b), a diphenylmethyl ester of the subject Compound (76c), there was formed the subject Compound (76c). Example 77 Production of sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-isopropoxyiminoacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (77c)]: Using Compound (R-3) and 2-(2-chloroacetamido-4-thiazolyl-(Z)-2-isopropoxyiminoacetic acid, there was obtained diphenylmethyl 2-{(4S)-4-[2-(2-chloroacetamido-4-thiazolyl)-(Z)-2-isopropoxyiminoacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (77a)] through a reaction analogous to Example 1, and after this product was converted into Compound (77b), a diphenylmethyl ester of the subject Compound (77c), there was obtained the subject Compound (77c). Example 78 Production of sodium 2-[(4S)-4-trifluoroacetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (78b)]: Compound (R-3) and trifluoroacetic anhydride were stirred in dichloromethane under ice cooling, and the reaction solution was poured into water, followed by extraction with ethyl acetate. The organic layer was washed with aqueous sodium hydrogencarbonate solution, water and saturated aqueous sodium chloride solution, successively, and dried (MgSO₄). The solvent was distilled off, and the residue was chromatographed on a column of silica gel to give Compound (78a), a diphenylmethyl ester of the subject Compound (78b) and then, a reaction and treatment analogous to Example 2 (b) yielded the subject Compound (78b). Example 79 Production of disodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(1-carboxy-1-methylethoxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (79d)]: (a) Production of diphenylmethyl 2-{(4S)-4-{2-(2-chloroacetamido-4-thiazolyl)-(Z)-2-[1-methyl-1-(4-nitrobenzyloxycarbonyl)ethoxyimino]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (79a)]: Using Compound (R-3) and 2-(2-chloroacetamido-4-thiazolyl)-(Z)-2-[1-methyl-1-(4-nitrobenzyloxycarbonyl)ethoxyimino]acetic acid, there was obtained Compound (79a) by the procedure of Example 1 (a). (b) Production of diphenylmethyl 2-{(4S)-4-{2-(2-amino-4-thiazolyl)-(Z)-2-[1-methyl-1-(4-nitrobenzyloxycarbonyl)ethoxyimino]acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (79b)]: Compound (79a) was treated by the procedure of Example 1 (b), there was obtained Compound (79b). (c) Production of sodium 2-{(4S)-4-{2-(2-amino-4-thiazolyl)-(Z)-2-[1-methyl-1-(4-nitrobenzyloxycarbonyl)ethoxyimino]acetamido)- 3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate [Compound (79c)]: Compound(79b) was treated in accordance with Example 1 (c) to give Compound (79c). (d) Production of the subject Compound (79d): Compound (79c) was treated the procedure of Example 2 (b) to give the subject compound (79d). Example 80 Production of sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(hydroxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (80b)]: (a) Production of diphenylmethyl 2-{(4S)-4-{2-(2-tritylamino-4-thiazolyl)-(Z)-2-(trityloxyimino)acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (80a)]: A solution of Compound (R-3) in N,N-dimethylformamide was added to a solution of 2-(2-tritylamino-4-thiazolyl)-(Z)-2-(trityloxyimino)acetic acid 2-benzothiazolylthio ester in tetrahydrofuran, followed by stirring at room temperature for 16 hours. The reaction solution was diluted with ethyl acetate, washed with aqueous sodium hydrogencarbonate solution and water, successively, and dried (Na₂SO₄). Then, the solvent was distilled off, and the residue was chromatographed on a column of silica gel to give Compound (80a). (b) Production of the subject Compound (80b): Formic acid (>98 %) was added to a dichloromethane solution of Compound (80a), followed by stirring at room temperature for 1 hour. After the solvent was distilled off under reduced pressure, the residue was dissolved in dichloromethane, and the solution was shaken after the addition of phosphate buffer of pH 7.0 (10 mℓ) containing sodium hydrogencarbonate (400 mg), followed by separating the aqueous layer. The organic layer was further extracted with a phosphate buffer of pH 7.0 (5 mℓ), and the aqueous layers were combined and concentrated under reduced pressure. The concentrate was chromatographed on a column of HP-20, followed by lyophilization to give the subject Compound (80b). Example 81 Production of sodium 2-[(4S)-4-isobutyloxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (81b)]: (a) Production of sodium diphenylmethyl 2-[(4S)-4-isobutyloxycarbonylamino-3-oxo-2-isoxazolidinyl -5-oxo-2-tetrahydrofurancarboxylate [Compound (81a)]; Using Compound (R-3) and isobutyl chlorocarbonate, there was obtained Compound (81a) by the procedure of Example 23 (a). (b) Production of the subject Compound (81b): Compound (81a) was treated by the procedure of Example 23 (b) to give the subject Compound (81b). Example 82 Production of diphenylmethyl 2-{(4S)-4-[N-(4-nitrobenzyloxycarbonyl)glycylamino]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (82)]: Using Compound (R-3), methyl chlorocarbonate and N-(4-nitrobenzyloxycarbonyl)glycine, there was obtained the subject Compound (82) by the procedure of Example 24 (a). Example 83 Production of diphenylmethyl 2-{(4S)-4-[N-(2,2,2-trichloroethoxycarbonyl)phenylglycylamino]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (83)]: Using Compound (R-3), methyl chlorocarbonate and N-(2,2,2-trichloroethoxycarbonyl)phenylglycine, there was obtained the subject Compound (83) by the procedure of Example 24 (a). Example 84 Production of sodium 2-{(4S)-4-[N-(benzyloxycarbonyl)-D-phenylglycylamino]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (84b)]: (a) Production of diphenylmethyl 2-{(4S)-4-[N-(benzyloxycarbonyl)D-phenylglycylamino]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (84a)]: Using Compound (R-3) and N-benzyloxycarbonyl-D-phenylglycine, there was obtained Compound (84a) by the procedure of Example 1 (a). (b) Production of the subject Compound (84b): Compound (84a) was treated by the procedure of Example 2 (b) to give the subject Compound (84b). Example 85 Production of 2-[(4S)-4-L-phenylglycylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylic acid [Compound (85b)]: (a) Production of diphenylmethyl 2-{(4S)-4-[N-(4-methoxybenzyloxycarbonyl)-L-phenylglycylamino]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (85a)]: Using Compound (R-3) and N-(4-methoxybenzyloxycarbonyl)-L-phenylglycine, there was obtained Compound (85a) by the procedure of Example 1 (a). (b) Production of the subject Compound (85b): Compound (85a) was treated by the procedure of Example 1 (c) to give the subject Compound (85b). Example 86 Production of 2-{(4S)-4-D-phenylglycylamino-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylic acid [Compound (86b)]: (a) Production of diphenylmethyl 2-{(4S)-4-[N-(4-methoxybenzyloxycarbonyl)-D-phenylglycylamino]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (86a)]: Using Compound (R-3) and N-(4-methoxybenzyloxycarbonyl)-D-phenylglycine, there was obtained Compound (86a) by the procedure of Example 1 (a). (b) Production of the subject Compound (86b): Compound (86a) was treated by the procedure of Example 1 (c) to give the subject Compound (86b). Example 87 Production of sodium 2-{(4S)-4-[(2S)-(2-hydroxy-2-phenyl)acetamido]-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (87b)]: (a) Production of diphenylmethyl 2-{(4S)-4-[(2S)-(2-hydroxy-2-phenyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofuran carboxylate [Compound (87a)]: Using Compound (R-3) and S-mandelic acid, there was obtained Compound (87a) by the procedure of Example 1 (a). (b) Production of the subject Compound (87b): Compound (87a) was treated by the procedure of Example 2 (b) to give the subject Compound (87b). Example 88 Production of sodium 2-{(4S)-4-[(2R)-(2-hydroxy-2-phenyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (88b)]: Using Compound (R-3) and R-mandelic acid, there was obtained Compound (88a), a diphenylmethyl ester of the subject Compound (88b), by the procedure of Example 87, and then, there was formed the subject Compound (88b). Example 89 Production of sodium 2-{(4S)-4-[2-(4-chlorophenyl)-2-hydroxyacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [compound (89b)]: Using Compound (R-3) and 4-chloro-DL-mandelic acid, there was obtained Compound (89a), a diphenylmethyl ester of the subject Compound (89b), by the procedure of Example 87, and then, there was formed the subject Compound (89b). Example 90 Production of sodium 2-{(4S)-4-[2-hydroxy-2-(4-hydroxyphenyl)-acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (90b)]: Using Compound (R-3) and 4-hydroxy-DL-mandelic acid, there was obtained Compound (90a), a diphenylmethyl ester of the subject Compound (90b), by the procedure of Example 87, and then, there was formed the subject Compound (90b). Example 91 Production of sodium 2-[(4S)-4-(2-hydroxypropionamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (91b)]: Using Compound (R-3) and DL-lactic acid, there was obtained Compound (91a), a diphenylmethyl ester of the subject Compound (91b), by the procedure of Example 87, and then, there was formed the subject Compound (91b). Example 92 Production of disodium 2-[(4S)-4-(2-carboxy-2-phenylacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (92b)]: Using Compound (R-3) and monodiphenylmethyl DL-phenylmalonate, there was obtained Compound (92a), a bis(diphenylmethyl ester) of the subject Compound (92b), by the procedure of Example 87, and then, there was formed the subject Compound (92b). Example 93 Production of sodium 2-[(4S)-4-benzyloxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (93b)]: Using Compound (R-3) and benzyloxycarbonyl chloride, there was obtained Compound (93a), a diphenylmethyl ester of the subject Compound (93b), by the procedure of Example 5, and then, there was formed the subject Compound (93b). Example 94 Production of sodium 2-((4S)-4-pyruvamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate [Compound (94b)]; Using Compound (R-3) and pyruvic acid, there was obtained Compound (94a), a diphenylmethyl ester of the subject Compound (94b), by the procedure of Example 87, and then, there was formed the subject Compound (94b). Example 95 Production of pivaloyloxymethyl 2-{(4S)-4-[(2R)-(2-hydroxy-2-phenyl)acetamido]-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate [Compound (95)]: Using Compound (88b) and chloromethyl pivalate, there was obtained the subject Compound (95) by the procedure of Example 28 (c). Example 96 Production of diphenylmethyl 2-[(4S)-4-(4-nitrobenzylidene)amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (96)]: Molecular sieves 4A was added to a dichloromethane solution of Compound (R-3) and 4-nitrobenzaldehyde, followed by stirring at room temperature for 8 hours. Molecular sieves was filtered off, and the filtrate was concentrated to dryness under reduced pressure. Ether was added to the residue, which was converted into powder to give the subject Compound (96). Example 97 Production of sodium 2-{(4S)-4-[2-(3-chloro-6-pyridazinylthio)acetamido]-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (97b)]: Using Compound (14a) and 3-chloro-6-pyridazinethiol sodium salt, there was obtained Compound (97a), a diphenylmethyl ester of the subject Compound (97b), by the procedure of Example 15, and then, there was formed the subject Compound (97b). Example 98 Production of sodium 2-[(45)-4-(2-phenylthioacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (98b)]: Using Compound (R-3) and phenylthioacetic acid, there was obtained Compound (98a), a diphenylmethyl ester of the subject Compound (98b), by the procedure of Example 1 (a), and then, there was formed the subject Compound (98b) by the procedure of Example 1 (c). Example 99 Production of sodium 2-[(4S)-4-(2-ethoxydithiocarbonylacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (99b)]: Using Compound (14a) and potassium ethylxanthate, there was obtained Compound (99a), a diphenylmethyl ester of the subject Compound (99b), by the procedure of Example 15, and then, there was formed the subject Compound (99b). Below are given the reaction conditions of Examples 38 to 99 as well as the yields and typical physico-chemical properties of the compounds obtained. Example 100 Production of sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(ethoxyimino)acetamido]-3-oxo-2-isoxazolidinyl} -5-oxo-2-tetrahydrofurancarboxylate [Compound (100)]: (a) Compound (R-3) was dissolved in a solvent mix of ethyl acetate anaphosphate buffer (pH 7.0), with 10% palladium-carbon added. The resulting solution was stirred in hydrogen stream under ice-cooling for 1.5 hours. After catalyst removal by filtration and water rinsing, the filtrate and the rinsing liquid were combined and the aqueous layer separated. Tetrahydrofuran was added to the aqueous layer, with sodium bicarbonate and 2-(2-chloroacetamido-4-thiazolyl)-(Z)-2-ethoxyiminoacetyl chloride hydrochloride added; the resulting solution was stirred under ice-cooling for 30 minutes. Tetrahydrofuran was vaporized under reduced pressure and the resulting aqueous layer rinsed with ethyl acetate. (b) Tetrahydrofuran and sodium N-methyldithiocarbamate were next added to the aqueous layer; the resulting solution was stirred at room temperature for 30 minutes. Tetrahydrofuran was vaporized under reduced pressure. After rinsing with ethyl acetate, the resulting concentrate was subjected to column chromatography using HP-20. The fraction eluted with 10% ethanol, after concentration, was subjected to freeze-drying, yielding Compound(100). Example 101 Production of sodium 2-{(4S)-4-[2-(2-amino-5-chloro-4-thiazolyl)-(Z)-2-(methoxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (101)]: Compound (101) was obtained via reaction by a method analogous to Example 100, using Compound (R-3) and 2-(5-chloro-2-chloroacetamido-4-thiazolyl)-(Z)-2-methoxyiminoacetyl chloride hydrochloride. Example 102 Production of sodium 2-{(4S)-4-[2-4-ethyl-2,3-dioxo-1-piperazinocarboxamido) -2-thienylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (102b)]: (a) Production of a diphenylmethyl ester of Compound (102b) [Compound (102a)]: Compound (102a) was obtained via reaction by a method analogous to Example 1 (a), using Compound (R-3) and 2-(4-ethyl-2,3-dioxo-1-piperazinylcarboxamido)-2-thienylacetic acid. (b) Production of Compound (102b): Compound (102b) was obtained via reaction on Compound (102a) by a method analogous to Example 1 (c). Example 103 Production of sodium 2-((4S)-4-ureido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate [Compound (103b)]: (a) Production of a diphenylmethyl ester of Compound (103b) [Compound (103a)]: An aqueous solution of potassium isocyanate was added to an acetic solution of Compound (R-3), the obtained solution being stirred at room temperature for 2 hours. The reaction solution obtained was added to water and eluted with ethyl acetate. The organic layer, after rinsing with water, an aqueous solution of sodium bicarbonate and saturated saline solution, was in turn dried (Na₂SO₄). After the solvent was vaporized off, the residue was refined by column chromatography using silica gel, yielding Compound (103a). (b) Production of Compound (103b): Compound (103b) was obtained via reaction with Compound (103a) by a method analogous to Example 2 (b). Example 104 Production of sodium 2-((4S)-4-phenylureylene-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate [Compound (104b)]: (a) Production of a diphenylmethyl ester of Compound (104b) [Compound (104a)]: Phenylisocyanate was added to a dichloromethane solution of Compound (R-3), and stirred at room temperature for 10 minutes. The solvent was then vaporized off. The residue was refined by column chromatography using silica gel, yielding Compound (104a). (b) Production of Compound (104b): Compound (104b) was obtained via reaction with Compound (104a) by a method analogous to Example 2 (b). Example 105 Production of sodium 2-{(4S)-4-[2-(pyridyl)acetamido] -3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (105)]: Compound (105) was obtained by a method analogous to Example 100 (a), using Compound (R-3) and 2-pyridylacetyl chloride hydrochloride. Example 106 Production of sodium 2-{(4S)-4-[2-(4-chlorophenyl) acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (106)]: Compound (106) was obtained by a method analogous to Example 100 (a), using Compound (R-3) and 4-chlorophenyl acetyl chloride. Example 107 Production of sodium 2-{(4S)-4-[(2-chloro-2-phenyl) acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (107)]: Compound (107) was obtained by a method analogous to Example 100 (a), using Compound (R-3) and 2-chloro-2-phenylacetyl chloride. Example 108 Production of sodium 2-{(4S)-4-[2-(3-pyridylthio) acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (108b)]: A diphenylmethyl ester of Compound (108b) [Compound (108a)] was first obtained by a method analogous to Example 15, using Compound (14a) and sodium 3-pyridinethiol, and then by a method analogous to Example 1 (c). Example 109 Production of sodium 2-{(4S)-4-[2-(4-chlorophenylthio) acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate [Compound (109b)]: Diphenylmethyl ester of Compound (109b) [Compound (109a)] was obtained by a method analogous to Example 15, using Compound (14a) and sodium 4-chlorophenylthiol, Compound (109b) was then obtained. Example 110 Production of sodium 2-[(4S)-4-(2-isopropylphenoxycarbonylamino)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (110b)]: Compound (110a), a diphenylmethyl ester of Compound (110b), was obtained by a method analogous to Example 5, using Compound (R-3) and 2-isopropylphenoxycarbonyl chloride, Compound (110b) was then obtained by a method analogous to Example 2 (b). Example 111 Production of sodium 2-((4S)-4-difluoroacetamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate [Compound (111b)]: A diphenylmethyl ester of Compound (111b) [Compound (111a)] was obtained by a method analogous to Example 1 (a),using Compound (R-3) and difluoroacetic acid; Compound (111b) was then obtained by a method analogous to Example 2 (b). Example 112 Production of sodium 2-[(4S)-4-(3-chloro)propionamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (112)]: Compound (112) was obtained by a method analogous to Example 100 (a), using Compound (R-3) and 3-chloropropionyl chloride. Example 113 Production of pivaloyloxymethyl 2-((4S)-4-chloroacetamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate [Compound (113)]: Compound (113) was obtained by a method analogous to Example 17, using Compound (14b) and chloromethyl pivalate. Example 114 Production of pivaloyloxymethyl 2-[(4S)-4-(2-phenylthioacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (114)]: Compound (114) was obtained by a method analogous to Example 17, using Compound (98b) and chloromethyl pivalate. Example 115 Production of sodium 2-((4S)-4-propionamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate [Compound (115b)]: A diphenylmethyl ester of Compound (115b) [Compound (115a)] was obtained by a method similar to that shown in Example 5, using Compound (R-3) and propyonyl chloride Compound (115b) was then obtained by a method analogous to Example 2 (b). Example 116 Production of pivaloyloxymethyl 2-((4S)-4-benzyloxycarbonylamino-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate [Compound (116)]: Compound (116) was obtained by a method analogous to Example 17, using Compound (93b) and chloromethyl pivalate. Example 117 Production of pivaloyloxymethyl 2-((4S)-4-bromoacetamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate [Compound (117)]: Compound (116) was dissolved in ethyl acetate with 5% palladium-carbon added. The solution obtained was stirred in hydrogen stream under ice-cooling for 1 hour. After the catalyst was removed by filtration, DMA and bromoacetyl bromide were added and the solution stirred under ice-cooling for 0.5 hour. The organic layer, after rinsing with water, was dried (Na₂SO₄) to vaporize off the solvent. The residue was refined by column chromatography using silica gel, yielding Compound (117). Example 118 Production of pivaloyloxymethyl 2-[(4S)-4-(2,4-hexadiene)amido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (118)]: Compound (116) was subjected to catalytic reduction by a method analogous to Example 117. After the catalyst was removed by filtration, the filtrate was concentrated to dryness. The residue obtained was dissolved in DMF; sorbic acid, DCC and HOBT were then added and the solution stirred at room temperature for 1 hour. Ethyl acetate was added to the reaction mixture obtained, the crystals separated being removed by filtration. The organic layer, after rinsing with water, was dried (Na₂SO₄). The solvent was vaporized off. The residue was refined by column chromatography using silica gel, yielding Compound (118). Example 119 Production of pivaloyloxymethyl 2-[(4S)-4-(2-thienyl)acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (119)]: Compound (119) was obtained by a method analogous to of Example 117, using Compound (116) and thienylacetyl chloride. Hereinafter are listed the reaction conditions, yields and physico-chemical properties of the compounds produced in Examples 100 to 119. Example 120 Production of pivaloyloxymethyl 2-[(4S)-4-(hexahydro-1H-azepin-1-yl)methyleneamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (120)]: Compound (116) was subjected to catalytic reduction by a method analogous to Example 117. After removing the catalyst by filtration, to the filtrate were added 1-hexamethyleneiminecarboxyaldehyde dimethylacetal and a catalytic amount of boron trifluoride under ice-cooling and the mixture was stirred at room temperature for 20 hours. The solvent was removed by evaporation under reduced pressure, and then the residue was subjected to purification by column chromatography using Florisil to give the subject Compound (120). Example 121 Production of diphenylmethyl 2-[(4S)-4-(tert-butyldimethylsilyl)amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (121)]: To a dimethylformamide solution of Compound (R-3) was added tert-butyldimethylsilyl chloride and triethylamine, and then the mixture was stirred at room temperature for one hour. The reaction solution was added to water-ethyl acetate and the mixture was shaken. The organic layer was recovered, washed with water and dried (Na₂SO₄). The solvent was removed by evaporation under reduced pressure to give the subject Compound (121). Example 122 Production of diphenylmethyl 2-[(4S)-4-tert-butyldiphenylsilyl)amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (122)]: Using Compound (R-3) and tert-butyl-diphenylsilyl chloride, there was obtained the subject Compound (122) by the procedure of Example 121. Example 123 Production of sodium 2-[(4S)-3-diphenylphosphorylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (123b)]: To a dimethylformamide solution of Compound (R-3) was added diphenyl phosphorochloridate under ice-cooling, and the mixture was stirred for one hour. The reaction solution was added to water, and the mixture was subjected to extraction with ethyl acetate. The ethyl acetate layer was washed with water and then dried (Na₂SO₄). The solvent was removed by evaporation under reduced pressure, and then the residue was subjected to purification by silica gel column chromatography to give Compound (123a), a diphenylmethyl ester of the subject Compound (123b). Then, the thus obtained Compound (123a) was treated by the procedure of Example 2(b) to give the subject Compound (123b). Example 124 Production of diphenylmethyl 2-[(4S)-4-dimethylphosphorylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (124)]: Using Compound (R-3) and dimethyl phosphorochloridate, there was obtained the subject Compound (124) by the procedure of Example 123. Example 125 Production of sodium 2-[(4S)-4-ethylsulfonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (125b)]: To a dichloromethane solution of Compound (R-3) were added ethanesulfonylchloride and triethylamine under ice-cooling. The mixture was stirred at 0°C for 30 minutes, and then at room temperature for 90 minutes. The reaction mixture was washed with water and then dried (Na₂SO₄). The solvent was removed by evaporation under reduced pressure, and then the residue was subjected to purification by silica gel chromatography to give Compound (125a), a diphenyl ester of the subject Compound (125b). Then, the thus obtained Compound (125a) was treated by the procedure of Example 2(b) to give the subject Compound (125b). Example 126 Production of sodium 2-[(4S)-4-vinylsulfonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (126)]: Using Compound (R-3) and 2-chloroethanesulfonyl chloride, there was obtained the subject Compound (126) by the procedure of Example 125 and then by the procedure of Example 1(c). Example 127 Production of 2-[(4S)-4-thienylacetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarbonylanilide [Compound (127)]: To the suspension of Compound (5b) in dichloromethane was added trimethylacetyl chloride at 0°C, and then the mixture was stirred at 0°C for one hour. To the resultant was added aniline, and then the mixture was stirred at room temperature for one hour. The reaction mixture was washed with water and dried (Na₂SO₄). The solvent was removed by evaporation under reduced pressure, and the residue was subjected to purification by column chromatography using Florisil to give Compound (127) as a colourless oily product. Example 128 Production of 2-[(4S)-4-benzyloxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarbonylanilide [Compound (128)]: Using Compound (93b) and aniline, there was obtained the subject Compound (128) as colorless crystals by the procedure of Example 127. Example 129 Production of 2-[(4S)-4-benzyloxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarbonylpyrrolidinamide [Compound (129)]: Using Compound (93b) and pyrrolidine, thus was obtained the subject Compound (129) as a colorless oily product by the procedure of Example 127. Example 130 Production of 2-[(4S)-4-thienylacetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarbonylpyrrolidinamide [Compound (13O)]. Using Compound (5b) and pyrrolidine, there was obtained the subject Compound (130) as acolorless oily product by the procedure of Example 127. Example 131 Production of 2-[(4S)-4-thienylacetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarbonylpropylamine [Compound (131)]: Using Compound (5b) and propylamine, there was obtained the subject Compound (130) as a colorless oily product by the procedure of Example 127. Example 132 Production of sodium 2-[(4S)-4-γ-D-glutamylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (132)]: Using Compound (R-3) and α-benzyl N-carbobenzoxy-D-glutamate, there was obtained the subject Compound (132) by the procedure of Example 1(a) and then by the procedure of Example 2(b). Example 133 Production of sodium 2-[(4S)-4-(2-hydroxy)isobutyrylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate [Compound (133)]: Using Compound (R-3) and 2-hydroxyisobutyric acid, there was obtained the subject Compound (133) by the procedure of Example 1 (a) and then by the procedure of Example 2 (b). Below are given the reaction conditions of Examples 120 to 133 as well as the yields and typical physico-chemical properties of the compounds obtained.

Claims: Claims for the following Contracting States : BE, CH, DE, FR, GB, IT, LI, LU, NL, SE A 2-((4S)-amino-3-oxo-2-isoxasolidinyl)-5-oxo-2-tetrahydrofurancarboxylic acid derivative of the formula (I') or a pharmaceutically acceptable salt thereof, selected from: (1) sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(methoxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (2) sodium 2-{(4S)-4-[D-2-(4-ethyl-2,3-dioxo-1-piperazinocarboxamido)-2-phenylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (3) sodium 2-{(4S)-4-[D-2-(3-methylsulfonyl-2-oxoimidazolidine-1-carboxamido)-2-phenylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (4) sodium 2-{(4S)-4-[D-2-(3-furfurylidene-amino-2-oxoimidazolidine-1-carboxamido-2-phenylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (5) sodium 2-[(4S)-4-(2-thienylacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (6) sodium 2-[(4S)-4-(2-cyanoacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (7) sodium 2-{(4S)-4-[(1H)-tetrazolylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (8) sodium 2-[(4S)-4-(2-6-dimethoxybenzamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (9) sodium 2-[(4S)-4-(5-methyl-3-phenyl-2-isoxazoline -4-carboxamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (10) sodium 2-[(4S)-4-(2-ethoxynaphthalenyl-1-carboxamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (11) sodium 2-[(4S)-4-(2-cyanomethylthioacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (12) sodium 2-[(4S)-4-(2-difluoromethylthioacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (13) sodium 2-{(4S)-4-[(R)-2-(4-cyclohexyl-2,3-dioxo-1-piperazinocarboxamido-2-phenylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (14) sodium 2-((4S)-4-chloroacetamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (15) sodium 2-{(4S)-4-[2-(4-pyridylthio)acetamido]-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (16) methyl 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (17) pivaloyloxymethyl 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (18) 3,5-dinitrobenzyl 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (19) p-bromophenacyl 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (20) p-bromobenzyl 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (21) sodium 2-[(4S)-4-formylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (22) sodium 2-[(4S)-4-n-butyrylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (23) sodium 2-[(4S)-4-methoxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (24) sodium 2-[(4S)-4-(N-benzyloxycarbonyl)-glycylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (25) sodium 2-[(4S)-4-benzoylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (26) sodium 2-[(4S)-4-phenylacetylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (27) sodium 2-[(4S)-4-nicotinylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (28) pivaloyloxymethyl 2-[(4S)-4-phenoxyacetylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (29) sodium 2-[(4S)-4-(p-toluenesulfonyl)amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (30) diphenylmethyl 2-[(4S)-4-(p-bromobenzoyl)-amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (31) diphenylmethyl 2-[(4S)-4-(N-benzyloxy-carbonyl-D-alanyl)amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (32) 2-[(4S)-4-dimethylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylic acid; (33) sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (34) sodium 2-[4-methoxy-4-(2-thienylacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (35) disodium 2-[(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(carboxymethyloxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (38) 2-{(4S)-4-[2-(2-aminomethyl)phenylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylic acid; (39) sodium 2-[(4S)-4-(4-fluorobenzenesulfonyl-amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (40) sodium 2-{(4S)-4-(2-[1-(2-dimethylaminoethyl)-1H-5-tetrazolylthio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (41) sodium 2-{(4S)-4-[2-(4-methyl-4H-1,2,4-triazolyl-3-ylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (42) sodium 2-{(4S)-4-[(2R,3S)-2-(4-ethyl-2,3-dioxo-1-piperazinecarboxamido)-3-formyloxybutylamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (43) disodium 2-[(4S)-4-(2-phenyl-2-sulfoacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (44) sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(E)-2-methoxyiminoacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (45) sodium 2-[(4S)-4-(2-trimethylsilyl)-ethoxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (46) sodium 2-[(4S)-4-(1-aminocyclohexylcarbonylamino)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylic acid; (47) sodium 2-{(4S)-4-[3-(2,6-dichlorophenyl)-5-methyl-4-isoxazolylcarbonylamino]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (48) sodium 2-{(4S)-4-[2-(2-pyridylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (49) sodium 2-{(4S)-4-[2-(4-pyridylmethylthio)-acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (50) sodium 2-{(4S)-4-[2-(2-pyrimidinylthio)-acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (51) sodium 2-{(4S)-4-{2-[(E)-2-(acetamidovinyl)thio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (52) sodium 2-[(4S)-4-cyclopropylcarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (53) sodium 2-[(4S)-4-methoxalylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (54) sodium 2-[(4S)-4-acrylamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (55) sodium 2-{(4S)-4-[2-(2-chloro-4-pyridylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (56) sodium 2-[(4S)-4-(2-acetamido-5-oxo-2-tetrahydrofurancarbonylamino)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (57) sodium 2-{(4S)-4-[2-(1-pyrazolyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (58) sodium 2-{(4S)-4-[2-(5-amino-1,2,4-thiadiazole-3-yl)-(Z)-2-ethoxyiminoacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (59) sodium 2-{(4S)-4-[2-(3-pyridazinylthio)-acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (60) sodium 2-[(4S)-4-dichloroacetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (61) sodium 2-{(4S)-4-[(2R,3S)-2-(4-ethyl-2,3-dioxo-1-piperazinecarboxamido)-3-hydroxybutyramido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (62) sodium 2-{(4S)-4-[2-(5-trifluoromethyl-1,3,4-thiadiazol-2-ylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (63) sodium 2-{(4S)-4-{2-[1-ethoxy(hydroxy)phosphinylmethyl-1H-5-tetrazolylthio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (64) sodium 2-{(4S)-4-{2-[5-(2-diethoxyphosphinylethylthio)-1,3,4-thiadiazolylthio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (65) sodium 2-{(4S)-4-[2-(1-dimethylamino-1H-5-tetrazolylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (66) sodium 2-{(4S)-4-[2-(4,5-dimethyl-2-thiazolylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (67) sodium 2-{(4S)-4-[2-(4,5-dimethyl-2-oxa-zolylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (68) sodium 2-{(4S)-4-[2-(5-methoxymethyl-1,3,4-thiadiazol-2-ylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (69) sodium 2-{(4S)-4-[2-(5-methylsulfonyl-methyl-1,3,4-thiadiazol-2-ylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (70) sodium 2-{(4S)-4-[2-(4-ethyl-4H-1,2,4-triazol-3-ylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (71) disodium 2-{{4S)-4-[2-(5-carboxymethyl-1,3,4-thiadiazol-2-ylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (72) sodium 2-{(4S)-4-{2-[1-(2-hydroxyethyl)-1H-5-tetrazolylthio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (73) sodium 2-{(4S)-4-{2-[1-(3-dimethylamino-propyl)-1H-5-tetrazolylthio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (74) 2-[(4S)-4-(2-amino-3-sulfamoylpropionamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylic acid; (75) sodium 2-{(4S)-4-[2-(4-cyano-3-hydroxy-5-isothiazolylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (76) sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-2-oxoacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (77) sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-isopropoxyiminoacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (78) sodium 2-[(4S)-4-trifluoroacetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (79) disodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(1-carboxy-1-methylethoxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (80) sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(hydroxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (81) sodium 2-[(4S)-4-isobutyloxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (82) diphenylmethyl 2-{(4S)-4-[N-(4-nitrobenzyloxycarbonyl)glycylamino]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (83) diphenylmethyl 2-{(4S)-4-[N-(2,2,2-trichloroethoxycarbonyl)phenylglycylamino]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (84) sodium 2-{(4S)-4-[N-(benzyloxycarbonyl)-D-phenylglycylamino]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (85) 2-[(4S)-4-L-phenylglycylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylic acid; (86) 2-{(4S)-4-D-phenylglycylamino-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylic acid; (87) sodium 2-{(4S)-4-[(2S)-(2-hydroxy-2-phenyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (88) sodium 2-{(4S)-4-[(2R)-(2-hydroxy-2-phenyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (89) sodium 2-{(4S)-4-[2-(4-chlorophenyl)-2-hydroxyacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (90) sodium 2-{(4S)-4-[2-hydroxy-2-(4-hydroxyphenyl)-acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (91) sodium 2-[(4S)-4-(2-hydroxypropionamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (92) disodium 2-[(4S)-4-(2-carboxy-2-phenylacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (93) sodium 2-[(4S)-4-benzyloxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (94) sodium 2-((4S)-4-pyruvamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (95) piveloyloxymethyl 2-{(4S)-4-[(2R)-(2-hydroxy-2-phenyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (96) diphenylmethyl 2-[(4S)-4-(4-nitrobenzylidene)amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (97) sodium 2-{(4S)-4-[2-(3-chloro-6-pyridazinylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (98) sodium 2-[(4S)-4-(2-phenylthioacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (99) sodium 2-[(4S)-4-(2-ethoxydithiocarbonylacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (100) sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(ethoxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (101) sodium 2-{(4S)-4-[2-(2-amino-5-chloro-4-thiazolyl)-(Z)-2-(methoxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (102) sodium 2-{(4S)-4-[2-4-ethyl-2,3-dioxo-1-piperazinocarboxamido)-2-thienylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (103) sodium 2-((4S)-4-ureido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (104) sodium 2-((4S)-4-phenylureylene-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (105) sodium 2-{(4S)-4-[2-(pyridyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (106) sodium 2-{(4S)-4-[2-(4-chlorophenyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (107) sodium 2-{(4S)-4-[(2-chloro-2-phenyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (108) sodium 2-{(4S)-4-[2-(3-pyridylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (109) sodium 2-{(4S)-4-[2-(4-chlorophenylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (110) sodium 2-[(4S)-4-(2-isopropylphenoxy-carbonylamino)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (111) sodium 2-((4S)-4-difluoroacetamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (112) sodium 2-[(4S)-4-(3-chloro)propionamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (113) pivaloyloxymethyl 2-((4S)-4-chloroacetamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (114) pivaloyloxymethyl 2-[(4S)-4-(2-phenylthioacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (115) sodium 2-((4S)-4-propionamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (116) pivaloyloxymethyl 2-((4S)-4-benzyloxy-carbonylamino-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (117) pivaloyloxymethyl 2-((4S)-4-bromoacetamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (118) pivaloyloxymethyl 2-[(4S)-4-(2,4-hexadiene)amido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (119) pivaloyloxymethyl 2-[(4S)-4-(2-thienyl)-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (120) pivaloyloxymethyl 2-[(4S)-4-(hexahydro-1H-azepin-1-yl)methyleneamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (121) diphenylmethyl 2-[(4S)-4-(tert-butyl-dimethylsilyl)amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (122) diphenylmethyl 2-[(4S)-4-tert-butyl-diphenylsilyl)amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (123) sodium 2-[(4S)-3-diphenylphosphorylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (124) diphenylmethyl 2-[(4S)-4-dimethyl-phosphorylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (125) sodium 2-[(4S)-4-ethylsulfonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofuran-carboxylate; (126) sodium 2-[(4S)-4-vinylsulfonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (127) 2-[(4S)-4-thienylacetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarbonylanilide; (128) 2-[(4S)-4-benzyloxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarbonylanilide; (129) 2-[(4S)-4-benzyloxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarbonylpyrrolidinamide; (130) 2-[(4S)-4-thienylacetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarbonylpyrrolidinamide; (131) 2-[(4S)-4-thienylacetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarbonylpropylamine; (132) sodium 2-[(4S)-4-γ-D-glutamylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; and (133) sodium 2-[(4S)-4-(2-hydroxy)isobutyryl-amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; A pharmaceutical composition for inhibiting the growth of microorganisms which contains an effective amount of a compound (I'), or a pharmaceutically acceptable salts thereof, as defined in Claim 1, together with a pharmaceutically acceptable carrier or diluent therefor. A compound (I'), or a pharmaceutically acceptable salt thereof, as defined in Claim 1, for use in the preparation of a pharmaceutical composition for inhibiting the growth of microorganisms. Claims for the following Contracting State : AT A pharmaceutical composition for inhibiting the growth of microorganisms, which contains an effective amount of a 2-((4S)-amino-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylic acid derivative, compound (I'), or a pharmaceutically acceptable salt thereof, selected from: (1) sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(methoxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (2) sodium 2-{(4S)-4-(D-2-(4-ethyl-2,3-dioxo-1-piperazinocarboxamido)-2-phenylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (3) sodium 2-{(4S)-4-[D-2-(3-methylsulfonyl-2-oxoimidazolidine-1-carboxamido)-2-phenylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (4) sodium 2-{(4S)-4-[D-2-(3-furfurylidene-amino-2-oxoimidazolidine-1-carboxamido-2-phenylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (5) sodium 2-[(4S)-4-(2-thienylacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (6) sodium 2-[(4S)-4-(2-cyanoacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (7) sodium 2-{(4S)-4-[(1H)-tetrazolylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (8) sodium 2-[(4S)-4-(2-6-dimethoxybenzamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (9) sodium 2-[(4S)-4-(5-methyl-3-phenyl-2-isoxazoline -4-carboxamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (10) sodium 2-[(4S)-4-(2-ethoxynaphthalenyl-1-carboxamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (11) sodium 2-[(4S)-4-(2-cyanomethylthioacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (12) sodium 2-[(4S)-4-(2-difluoromethylthioacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (13) sodium 2-{(4S)-4-[(R)-2-(4-cyclohexyl-2,3-dioxo-1-piperazinocarboxamido-2-phenylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (14) sodium 2-((4S)-4-chloroacetamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (15) sodium 2-{(4S)-4-[2-(4-pyridylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (16) methyl 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (17) pivaloyloxymethyl 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (18) 3,5-dinitrobenzyl 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (19) p-bromophenacyl 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (20) p-bromobenzyl 2-[(4S)-4-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (21) sodium 2-[(4S)-4-formylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (22) sodium 2-[(4S)-4-n-butyrylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (23) sodium 2-[(4S)-4-methoxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (24) sodium 2-[(4S)-4-(N-benzyloxycarbonyl)-glycylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (25) sodium 2-[(4S)-4-benzoylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (26) sodium 2-[(4S)-4-phenylacetylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (27) sodium 2-[(4S)-4-nicotinylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (28) pivaloyloxymethyl 2-[(4S)-4-phenoxyacetylamino3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (29) sodium 2-[(4S)-4-(p-toluenesulfonyl)amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (30) diphenylmethyl 2-[(4S)-4-(p-bromobenzoyl)-amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (31) diphenylmethyl 2-[(4S)-4-(N-benzyloxy-carbonyl-D-alanyl)amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (32) 2-[(4S)-4-dimethylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylic acid; (33) sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (34) sodium 2-[4-methoxy-4-(2-thienylacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (35) disodium 2-[(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(carboxymethyloxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (38) 2-{(4S)-4-[2-(2-aminomethyl)phenylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylic acid; (39) sodium 2-[(4S)-4-(4-fluorobenzenesulfonyl-amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (40) sodium 2-{(4S)-4-{2-[1-(2-dimethylaminoethyl)-1H-5-tetrazolylthio]acetamido}-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (41) sodium 2-{(4S)-4-[2-(4-methyl-4H-1,2,4-triazolyl-3-ylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (42) sodium 2-{(4S)-4-[(2R,3S)-2-(4-ethyl-2,3-dioxo-1-piperazinecarboxamido)-3-formyloxybutylamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (43) disodium 2-[(4S)-4-(2-phenyl-2-sulfoacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (44) sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(E)-2-methoxyiminoacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (45) sodium 2-[(4S)-4-(2-trimethylsilyl)-ethoxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (46) sodium 2-[(4S)-4-(1-aminocyclohexylcarbonylamino)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylic acid; (47) sodium 2-{(4S)-4-[3-(2,6-dichlorophenyl)-5-methyl-4-isoxazolylcarbonylamino]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (48) sodium 2-{(4S)-4-[2-(2-pyridylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (49) sodium 2-{(4S)-4-[2-(4-pyridylmethylthio)-acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (50) sodium 2-{(4S)-4-[2-(2-pyrimidinylthio)-acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (51) sodium 2-{(4S)-4-{2-[(E)-2-(acetamidovinyl)thio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (52) sodium 2-[(4S)-4-cyclopropylcarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (53) sodium 2-[(4S)-4-methoxalylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (54) sodium 2-[(4S)-4-acrylamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (55) sodium 2-{(4S)-4-[2-(2-chloro-4-pyridylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (56) sodium 2-[(4S)-4-(2-acetamido-5-oxo-2-tetrahydrofurancarbonylamino)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (57) sodium 2-{(4S)-4-[2-(1-pyrazolyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (58) sodium 2-{(4S)-4-[2-(5-amino-1,2,4-thiadiazole-3-yl)-(Z)-2-ethoxyiminoacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (59) sodium 2-{(4S)-4-[2-(3-pyridazinylthio)-acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (60) sodium 2-[(4S)-4-dichloroacetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (61) sodium 2-{(4S)-4-[(2R,3S)-2-(4-ethyl-2,3-dioxo-1-piperazinecarboxamido)-3-hydroxybutyramido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (62) sodium 2-{(4S)-4-[2-(5-trifluoromethyl-1,3,4-thiadiazol-2-ylthio)acetamido]-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (63) sodium 2-{(4S)-4-{2-[1-ethoxy(hydroxy)phosphinylmethyl-1H-5-tetrazolylthio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (64) sodium 2-{(4S)-4-{2-[5-(2-diethoxyphosphinylethylthio)-1,3,4-thiadiazolylthio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (65) sodium 2-{(4S)-4-[2-(1-dimethylamino-1H-5-tetrazolylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (66) sodium 2-{(4S)-4-[2-(4,5-dimethyl-2-thiazolylthio)acetamido]-3-oxo-2-isoxazolidiny1}-5-oxo-2-tetrahydrofurancarboxylate; (67) sodium 2-{(4S)-4-[2-(4,5-dimethyl-2-oxa-zolylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (68) sodium 2-{((4S)-4-[2-(5-methoxymethyl-1,3,4-thiadiazol-2-ylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (69) sodium 2-{(4S)-4-[2-(5-methylsulfonyl-methyl-1,3,4-thiadiazol-2-ylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (70) sodium 2-{(4S)-4-[2-(4-ethyl-4H-1,2,4-triazol-3-ylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (71) disodium 2-{(4S)-4-[2-(5-carboxymethyl-1,3,4-thiadiazol-2-ylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (72) sodium 2-{(4S)-4-{2-[1-(2-hydroxyethyl)-1H-5-tetrazolylthio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (73) sodium 2-{(4S)-4-{2-[1-(3-dimethylamino-propyl)-1H-5-tetrazolylthio]acetamido}-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (74) 2-[(4S)-4-(2-amino-3-sulfamoylpropionamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylic acid; (75) sodium 2-{(4S)-4-[2-(4-cyano-3-hydroxy-5-isothiazolylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (76) sodium 2-{[(4S)-4-[2-(2-amino-4-thiazolyl)-2-oxoacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (77) sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-isopropoxyiminoacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (78) sodium 2-[(4S)-4-trifluoroacetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (79) disodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(1-carboxy-1-methylethoxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (80) sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(hydroxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (81) sodium 2-[(4S)-4-isobutyloxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (82) diphenylmethyl 2-{(4S)-4-[N-(4-nitrobenzyloxycarbonyl)glycylamino]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (83) diphenylmethyl 2-{(4S)-4-[N-(2,2,2-trichloroethoxycarbonyl)phenylglycylamino]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (84) sodium 2-{(4S)-4-[N-(benzyloxycarbonyl)-D-phenylglycylamino]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (85) 2-[(4S)-4-L-phenylglycylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylic acid; (86) 2-{(4S)-4-D-phenylglycylamino-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylic acid; (87) sodium 2-{(4S)-4-[(2S)-(2-hydroxy-2-phenyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (88) sodium 2-{(4S)-4-[(2R)-(2-hydroxy-2-phenyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (89) sodium 2-{(4S)-4-[2-(4-chlorophenyl)-2-hydroxyacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (90) sodium 2-{(4S)-4-[2-hydroxy-2-(4-hydroxyphenyl)-acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (91) sodium 2-[(4S)-4-(2-hydroxypropionamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (92) disodium 2-[(4S)-4-(2-carboxy-2-phenylacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (93) sodium 2-[(4S)-4-benzyloxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (94) sodium 2-((4S)-4-pyruvamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (95) pivaloyloxymethyl 2-{(4S)-4-[(2R)-(2-hydroxy-2-phenyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (96) diphenylmethyl 2-[(4S)-4-(4-nitrobenzylidene)amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (97) sodium 2-{(4S)-4-[2-(3-chloro-6-pyridazinylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (98) sodium 2-[(4S)-4-(2-phenylthioacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (99) sodium 2-[(4S)-4-(2-ethoxydithiocarbonylacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (100) sodium 2-{(4S)-4-[2-(2-amino-4-thiazolyl)-(Z)-2-(ethoxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (101) sodium 2-{(4S)-4-[2-(2-amino-5-chloro-4-thiazolyl)-(Z)-2-(methoxyimino)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (102) sodium 2-{(4S)-4-[2-4-ethyl-2,3-dioxo-1-piperazinocarboxamido)-2-thienylacetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (103) sodium 2-((4S)-4-ureido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (104) sodium 2-((4S)-4-phenylureylene-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (105) sodium 2-{(4S)-4-[2-(pyridyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (106) sodium 2-{(4S)-4-[2-(4-chlorophenyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (107) sodium 2-{(4S)-4-[(2-chloro-2-phenyl)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (108) sodium 2-{(4S)-4-[2-(3-pyridylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (109) sodium 2-{(4S)-4-[2-(4-chlorophenylthio)acetamido]-3-oxo-2-isoxazolidinyl}-5-oxo-2-tetrahydrofurancarboxylate; (110) sodium 2-[(4S)-4-(2-isopropylphenoxy-carbonylamino)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (111) sodium 2-((4S)-4-difluoroacetamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (112) sodium 2-[(4S)-4-(3-chloro)propionamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (113) pivaloyloxymethyl 2-((4S)-4-chloroacetamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (114) pivaloyloxymethyl 2-[(4S)-4-(2-phenylthioacetamido)-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (115) sodium 2-((4S)-4-propionamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (116) pivaloyloxymethyl 2-((4S)-4-benzyloxy-carbonylamino-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (117) pivaloyloxymethyl 2-((4S)-4-bromoacetamido-3-oxo-2-isoxazolidinyl)-5-oxo-2-tetrahydrofurancarboxylate; (118) pivaloyloxymethyl 2-[(4S)-4-(2,4-hexadiene)amido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (119) pivaloyloxymethyl 2-[(4S)-4-(2-thienyl)-acetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (120) pivaloyloxymethyl 2-[(4S)-4-(hexahydro-1H-azepin-1-yl)methyleneamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (121) diphenylmethyl 2-[(4S)-4-(tert-butyl-dimethylsilyl)amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (122) diphenylmethyl 2-[(4S)-4-tert-butyl-diphenylsilyl)amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (123) sodium 2-[(4S)-3-diphenylphosphorylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (124) diphenylmethyl 2-[(4S)-4-dimethyl-phosphorylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (125) sodium 2-[(4S)-4-ethylsulfonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (126) sodium 2-[(4S)-4-vinylsulfonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; (127) 2-[(4S)-4-thienylacetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarbonylanilide; (128) 2-[(4S)-4-benzyloxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarbonylanilide; (129) 2-[(4S)-4-benzyloxycarbonylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarbonylpyrrolidinamide; (130) 2-[(4S)-4-thienylacetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarbonylpyrrolidinamide; (131) 2-[(4S)-4-thienylacetamido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarbonylpropylamine; (132) sodium 2-[(4S)-4-γ-D-glutamylamino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; and (133) sodium 2-[(4S)-4-(2-hydroxy)isobutyryl-amino-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate; together with a pharmaceutically acceptable carrier or diluent therefor. The use of a compound (I'), or pharmaceutically acceptable salt thereof, as defined in Claim 1, in the preparation of a pharmaceutical composition for inhibiting the growth of microorganisms.

Inventors: HARADA, SETSUO, OCHIAI, MICHIHIKO, YOSHIOKA, KOICHI
Applicants: TAKEDA CHEMICAL INDUSTRIES, LTD.
Application year: 1985
Main classification: C07D413
IPC codes: C07D247, C07D413, A61K31, C07F7, C07D521, C07D333, A61K38, C07D237, C12P17, C12R1, C07K5, C07F9, C07D417, A61P31, C07D307, C07D407, C07D261