Baccatin derivatives and processes for preparing the same

Abstract: A compound represented by the formula [I]: wherein R³ represents a lower alkanoyl group; R⁴ represents a substituted or unsubstituted benzoyl group; ring A represents a substituted or unsubstituted cyclopropane ring; X represents a single bond or a group represented by -O-, -S- or -NH-; R represents a substituted or unsubstituted lower alkyl group wherein said lower alkyl group may have attached a cycloalkyl moiety; a substituted or unsubstituted aryl group or a substituted or unstibstituted aromatic heterocyclic group; E represents a hydrogen atom or a group represented by -CO(CH₂) n ZY; Y represents a residue obtained from an amino acid or a dipeptide by removing the hydroxyl group from one carboxyl group, wherein the existing amino group in said residue may be protected, and the existing carboxyl group in said residue may be esterified or amidated; Z represents a group represented by the formula -O- or -NH-; and n represents 1, 2, 3, 4, 5 or 6, and pharmaceutically acceptable salts thereof have excellent antitumor activity and therefore are useful in the prophylaxis or treatment of a wide range of tumors such as breast cancer, ovary cancer lung cancer and malignant melanoma.

Description: Technical Field The present invention relates to a novel baccatin derivative having antitumor activity, and to processes for preparing the same. Prior Art It is known that taxol [4α, 10β-diacetoxy-13α-[(2R,3S)-3-benzoylamino-2-hydroxy-3-phenylpropionyloxy]-2α-benzoyloxy-5β,20-epoxy-1β,7β-dihydroxytax-11-en-9-one] is a diterpenoid obtained from Taxus brevifolia, and has excellent antitumor activity on various kinds of cancers, but its water-solubility is extremely low, i.e. 0.004 mg/ml or less [Nature, Vol. 346, p. 464 (1993)], which is a clinical problem. In order to improve the antitumor activity of taxol, the modification of the hydroxyl group at the 10-position and/or the amino group in the side chain at the 13-position have been reported [e.g., Japanese Provisional Patent Publications Nos. 30478/1988 and 30479/1988, Tetrahedron Letters, Vol. 33, p. 5185 (1992) and Tetrahedron, Vol. 45, p. 4177 (1989) etc.]. Examples which improve the water-solubility of taxol by modifying the hydroxyl group in the side chain at the 13-position and/or the hydroxyl group at the 7-position with a hydrophilic group are disclosed in U.S. Patents Nos. 4960790, 5059699, and 5283253, and Japanese Provisional Patent Publication No. 1782/1994. U.S. Patent No. 4960790 discloses taxol derivatives obtained by modifying the hydroxyl group in the side chain at the 13-position and/or the hydroxyl group at the 7-position directly with the residues obtained from amino acids such as alanine, leucine and isoleucine. There have been described taxol derivatives obtained by modifying the hydroxyl group in the side chain at the 13-position with a group such as -CO-(CH y ) m -CO-NH-(CH 2 ) 2 -SO 3 -M (wherein y is 1 or 2, m is 1 to 3, M is a hydrogen atom, an alkali metal atom, and the like, e.g., the sodium 4-(2-sulfonatoethyl)amino-1,4-dioxobutyl group) in U.S. Patent No. 5059699. In Japanese Provisional Patent Publication No. 1782/1994, there have been described taxol derivatives obtained by esterifying the hydroxyl group in the side chain at the 13-position, the hydroxyl group at the 7-position, and/or the hydroxyl group at the 10-position with phosphoric acid or carbonic acid. Furthermore, in U.S. Patent No. 5283253, taxol derivatives obtained by modifying the amino group in the side chain at the 13-position with a furancarbonyl group or thiophenecarbonyl group and the hydroxyl group in the side chain at the 13-position and/or the hydroxyl group at the 7-position with a carboxyl group-substituted or carbamoyl group-substituted lower alkanoyl group and the like are described. Meanwhile, WO 94-10997 describes a taxol derivative which is obtained by replacing the phenyl group in the side chain at the 13-position by a cyclopropyl group, and having an acetoxy group at the 10-position. WO-A-94/21250 describes taxol derivatives having antitumor and antileukaemia activity, wherein in addition to an acylamino group at the 3 1 - position of the taxol skeleton there is also a substituent selected from H, alkyl, alkenyl, alkynyl, aryl or heteroaryl. US-A-5,284,865 describes taxol derivatives in which the aforesaid substituent is cyclohexyl. However, heretobefore, it has not been reported that a taxol derivative having high water-solubility, stability, and excellent antitumor activity has been used clinically. Brief Description of Invention An object of the present invention is to provide novel baccatin derivatives having excellent antitumor activity, and novel baccatin derivatives having excellent antitumor activity and improved water-solubility. Still another object of the present invention is to provide processes for preparing such novel baccatin derivatives. Detailed Description of the Invention The present invention relates to a compound represented by the formula [I]: wherein R 3 represents a C 2-7 alkanoyl group; R 4 represents a benzoyl group which may be substituted with a group selected from a C 1-6 alkyl group, a C 1-6 alkoxy group and a halogen atom; ring A is a cyclopropane ring which may be substituted with 1 or 2 groups selected from a halogen atom, a C 1-6 alkyl group, and a C 1-6 alkoxy group; X represents a single bond or a group represented by -O-,-S- or -NH-; R is a C 1-6 alkyl group which may be substituted with 1 to 3 groups selected from a halogen atom and a C 1-6 alkoxy group, wherein said C 1-6 alkyl group may have attached a 3- to 5-membered cycloalkyl moiety, a phenyl group which may be substituted with 1 or 2 C 1-6 alkoxy groups, a furyl group, or a thienyl group; E represents a hydrogen atom or a group represented by -CO(CH 2 ) n ZY; Y represents a residue obtained from asparagine, aspartic acid, glutamine, glutamic acid, proline, glycine, alanine, β-alanine, or a dipeptide consisting of these amino acids by removing the hydroxyl group from one carboxyl group, wherein the amino group existing in said residue may be protected with a benzyloxycarbonyl group, and the existing carboxyl group in said resident may be esterified with a C 1-6 alkyl group which may be substituted with a C 1-6 alkoxy group, or amidated; Z represents a group represented by the formula -O- or -NH-; and n represents 1,2,3,4,5 or 6, or a pharmaceutically acceptable salt thereof. The present invention also provides pharmaceutical compositions comprising a therapeutically effective amount of the above compound, or a pharmaceutically acceptable salt thereof, in admixture with a conventional pharmaceutically acceptable carrier or diluent. As the C 1-6 alkyl group having attached a 3- to 5- membered cycloalkyl moiety, there may be mentioned, for example, a cyclopropylmethyl group, cyclobutylmethyl group, or (2,2-dimethyl-cyclopropyl)methyl group. Further, as an example of the C 1-6 alkyl group having a substituent and also having attached a cycloalkyl moiety, there may be mentioned a (2,2-difluoro-3,3-dimethylcyclopropyl)methyl group. As a preferred example of the desired compound [I] in the present invention, may be mentioned a compound in which E is a group represented by -CO(CH 2 ) n ZY. As the most preferred desired compound (I), there may be mentioned that a compound in which ring A is a cyclopropane ring which may be substituted with a C 1-6 alkyl group and R is a C 1-6 alkyl group, furyl group or thienyl group is particularly preferred. As a compound exhibiting an excellent pharmaceutical effect, there may be mentioned a compound represented by the formula [I] in which R 3 is a acetyl group, R 4 is a benzoyl group, X is a group represented by -O-; R is a C 1-6 alkyl group; and Y is an asparaginyl group, aspartyl group, β-alanyl group, or prolyl group, wherein the existing carboxyl group in said residue may be esterified with a C 1-6 alkyl group, or amidated. As specific compounds, for example, there may be mentioned the compounds shown in Tables 1-7. As a preferred example of the desired compound [I] in the present invention, may be mentioned a compound in which E is a group represented by -CO(CH 2 ) n ZY. As a more preferred example of the desired compound [I], may be mentioned a compound in which Y is a residue obtained from an α- or β-amino acid, or a dipeptide consisting of these amino acids by removing a hydroxyl group from one carboxyl group, wherein the existing amino group in said residue may be protected, and the existing carboxyl group in said residue may be esterified, or amidated. As a further preferred compound of the desired compound [I] in the present invention, there may be mentioned a compound in which ring A is a cyclopropane ring which may be substituted with 1 or 2 groups selected from a halogen atom, a lower alkyl group, and a lower alkoxy group; R is a lower alkyl group which may be substituted with 1 to 3 groups selected from a halogen atom and a lower alkoxy group, wherein said lower alkyl group may have attached a 3- to 5-membered cycloalkyl moiety; a phenyl group which may be substituted with 1 or 2 lower alkoxy groups, a furyl group, or thienyl group; and Y is a residue obtained from a natural amino acid or an antipode thereof or a dipeptide consisting of a natural amino acid or an antipode thereof by removing a hydroxyl group from one carboxyl group, wherein the existing amino group in said residue may be protected with a benzyloxycarbonyl group or a lower alkyl group, and the existing carboxyl group in said residue may be esterified with a lower alkyl group which may be substituted with a lower alkoxy group, or amidated. As the most preferred desired compound [I], there may be mentioned a compound in which Y is a residue obtained from asparagine, aspartic acid, glutamine, glutamic acid, proline, glycine, alanine, β-alanine, or a dipeptide consisting of these amino acids by removing a hydroxyl group from one carboxyl group, wherein the existing amino group in said residue may be protected with a benzyloxycarbonyl group or a lower alkyl group, and the existing carboxyl group in said residue may be esterified with a lower alkyl group which may be substituted with a lower alkoxy group, or amidated; and a compound in which ring A is a cyclopropane ring which may be substituted with a lower alkyl group; R is a lower alkyl group, furyl group or thienyl group; Y is a residue obtained from asparagine, aspartic acid, glutamine, glutamic acid, proline, glycine, or β-alanine by removing the hydroxyl group from one carboxyl group, wherein the existing carboxyl group in said residue may be esterified with a lower alkyl group, or amidated, is particularly preferred. As a compound exhibiting an excellent pharmaceutical effect, there may be mentioned a compound represented by the formula [I] in which R 3 is an acetyl group, R 4 is a benzoyl group, X is a group represented by -O-; R is a lower alkyl group; and Y is an asparaginyl group, aspartyl group, β-alanyl group, or prolyl group, wherein the existing carboxyl group in said residue may be esterified with a lower alkyl group, or amidated. As specific compounds, for example, there may be mentioned the compounds shown in Tables 1-7. In the desired compound [I] in the present invention, various stereo isomers and optical isomers based on the two asymmetric carbon atoms of a substituted 3-cyclopropylpropionyloxy group bonded to the carbon atom at the 13-position of the taxane skeleton and an asymmetric carbon atom existing in a substituent thereof can exist. All of these stereoisomers, optical isomers, and mixtures thereof are included in the present invention. The desired compound [I] of the present invention can be used for medicinal purposes either in a free form or in the form of pharmaceutically acceptable salts thereof. As pharmaceutically acceptable salts, there may be mentioned acid addition salts with inorganic acids or organic acids such as the hydrochloride, sulfate, nitrate, hydrobromide, methanesulfonate, toluenesulfonate or acetate. The desired compound [I] of the present invention or pharmaceutically acceptable salts thereof can be administered either orally or parenterally, and it can be used as a suitable pharmaceutical preparation, for example, a tablet, a granule, a capsule, a powder, an injection, and an inhalation by a conventional process. The dose of the desired compound [I] of the present invention or a pharmaceutically acceptable salt thereof varies depending on the administration method, age, body weight, and state of a patient, but, in general, the daily dose is preferably about 5 to 200 mg/m 2 , particularly preferably 20 to 150 mg/m 2 . According to the present invention, the desired compound [I] can be prepared: (1) by reacting a compound represented by the formula [II]: wherein R 1 represents a hydroxyl protecting group; R 2 represents a hydroxyl protecting group; R 3 , R 4 , and ring A are the same as defined above, or a salt thereof with a compound represented by the formula [III]: RX-COOH wherein R and X are the sane as defined above, a salt thereof, or a reactive derivative thereof to obtain a compound represented by the formula [V]: wherein R 1 , R 2 , R 3 , R 4 , ring A, X, and R are the same as defined above, and removing the protecting groups of the hydroxyl groups at the 7-position and the 10-position in the compound; (2) by reacting the compound [II] or a salt thereof with the compound [III], a salt thereof, or a reactive derivative thereof, to obtain the compound [V], reacting the compound [V] with a compound represented by the formula [IV]: E'OH wherein E' is a group represented by -CO(CH 2 ) n ZY; Y, Z, and n are the same as defined above, a salt thereof, or a reactive derivative thereof, and removing the protecting groups of the hydroxyl groups at the 7-position and the 10-position in the compound obtained; or (3) by reacting the compound [II] or a salt thereof with the compound [III], a salt thereof, or a reactive derivative thereof, to obtain the compound [V], removing the protecting groups of the hydroxyl groups at the 7-position and the 10-position in the compound [V], and then reacting the resulting compound with a compound of the formula [IV], a salt thereof, or a reactive derivative thereof. In the process described above, by the reaction of the compound [II] or a salt thereof with the compound [III], a salt thereof, or a reactive derivative, the compound [V] can be prepared. By the reaction of the compound [V] with the compound [IV], a salt thereof, or a reactive derivative thereof, the removal of the protecting group of the hydroxyl group in the resulting compound, and if necessary, the removal of the amino protecting group and carboxyl group ester residue, a compound represented by the formula [I-a]: wherein R 1 , R 2 , R 3 , R 4 , ring A, X, R, and E' are the same as defined above, can be prepared. Also, according to the present invention, the compound [I-a] can be prepared by: (a) reacting the compound [II] or a salt thereof with the compound [III], a salt thereof, or a reactive compound to obtain the compound [V]; (b) reacting the compound [V] with a compound represented by the formula [VI]: R 5 Z(CH 2 ) n COOH wherein R 5 represents a hydroxyl or amino protecting group, Z and n are the same as defined above, a salt thereof, or a reactive derivative thereof; (c) removing the protecting group R 5 from the compound obtained to obtain a compound represented by the formula [VII]: wherein R 1 , R 2 , R 3 , R 4 , ring A, X, R, Z, and n are the same as defined above; (d) reacting the compound [VII] with a compound represented by the formula [VIII]: YOH wherein Y is the same as defined above; and (e) removing the hydroxyl protecting group, if necessary, removing the amino protecting group and the carboxyl group ester residue. Also, according to the present invention, by reacting a compound represented by the formula [IX]: wherein R 6 represents a substituted phenyl group, ring A, X, and R are the same as defined above, or a reactive derivative thereof with a compound represented by the formula [X]: wherein R 1 , R 2 , R 3 , and R 4 are the same as defined above, and then subjecting the resulting condensate to a cleavage reaction of the oxazolidine ring to obtain the compound [V], and removing the protecting groups of the hydroxyl groups at the 7-position and the 10-position in the copound [V], the compound represented by the formula [I-b]: wherein R 3 , R 4 , ring A, X, and R are the same as defined above, can be prepared. In the compound [IX], as the substituent of the phenyl group of R 6 , there may be mentioned electron donating groups, for example, an alkoxy group or an amino group. As the salt of the compound [II], there may be mentioned, for example, organic acid salts such as formate, acetate, methanesulfonate and p-toluenesulfonate and inorganic acid salts such as hydrochloride and hydrobromide. As the protecting group R 1 and R 2 of the hydroxyl groups at the 7-position and the 10-position in the taxane skeleton, there may be mentioned a lower alkanoyl group, 2,2,2-trichloroethoxycarbonyl group or triethylsilyl group, and these protecting groups R 1 and R 2 may be different protecting groups. As examples of different protecting groups, there may be mentioned that R 1 may be a 2,2,2-trichloroethoxycarbonyl group when R 2 is a triethylsilyl group. When the protecting groups in the compound [VI] are hydroxyl protecting groups, there may be mentioned conventional protecting groups such as the benzyl group. On the other hand, when the protecting groups in the compound [VI] are amino protecting groups, there may be mentioned conventional protecting groups such as the benzyloxycarbonyl group. As the reactive derivatives of the compound [III], the compound [IV] and the compound [VI], there may be mentioned an acid halide, an active ester and a mixed acid anhydride. As the reactive derivative of the compound [III], there also may be mentioned isocyanate. When the compound [III], the compound [IV], or the compound [VI] is used in the condensation, the condensing reaction can be carried out in the presence or absence of a dehydrating agent in a suitable solvent or without a solvent. As the dehydrating agent, there may be suitably used dicyclohexylcarbodiimide, carbonyldiimidazole, 1-methyl-2-bromopyridinium iodide or benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate. As the solvent, there may be suitably used dichloromethane, dimethyl ether, dimethylformamide, dioxane, tetrahydrofuran, or toluene. The present reaction proceeds suitably at -20 to 100 °C, particularly 0 to 30°C. On the other hand, when the reactive derivative of the compound [III], the compound [IV], or the compound [VI] is used in the condensation, the condensing reaction can be carried out in the presence or absence of an acid acceptor in a suitable solvent. As the acid acceptor, there may be suitably used an alkali metal hydride, an alkali metal carbonate, an alkali metal hydrogen carbonate, or an organic base (e.g., triethylamine, diisopropylethyl-amine, pyridine, 4-(N,N-dimethylamino)pyridine, or 1,8-diazabiclo [5.4.0] undec-7-ene). As the solvent, there may be suitably used dichloromethane, dimethyl ether, dimethylformamide, dioxane, tetrahydrofuran, or toluene. The present reaction proceeds suitably at -20 to 80 °C, particularly 0 to 30 °C. The condensing reaction of the compound [VIII] with the compound [VII] can be carried out in the presence of a dehydrating agent and an acid acceptor in a suitable solvent. As the dehydrating agent, there may be suitably used dicyclohexylcarbodiimide, carbonyldiimidazole, 1-methyl-2-bromopyridinium iodide, or benzotriazol-1-yloxytris(dimethylamino)phosphoniumhexafluorophosphate. As the acid acceptor, there may be suitably used an alkali metal hydride, an alkali metal carbonate, an alkali metal hydrogen carbonate, or an organic base (e.g., triethylamine, diisopropylethyl-amine, pyridine, 4-(N,N-dimethylamino)pyridine, or 1,8-diazabiclo [5.4.0] undec-7-ene). As the solvent, there may be suitably used dichloromethane, dimethyl ether, dimethylformamide, dioxane, tetrahydrofuran, or toluene. The present reaction proceeds suitably at -20 to 80 °C, particularly 0 to 30°C. The condensing reaction of the compound [IX] or a reactive derivative thereof with the compound [X] can be carried out in a suitable solvent. As the solvent, there may be suitably used dichloromethane, dimethyl ether, dimethylformamide, dioxane, tetrahydrofuran, or toluene. As the reactive derivative, there may be mentioned an acid halide (e.g., acid chloride, acid bromide, or acid iodide), an active ester (e.g., p-nitrophenyl ester), or a mixed acid anhydride [e.g., a mixed acid anhydride with benzoic acid which is substituted with 1-5 group(s) selected from a halogen atom, nitro group, a lower alkyl group, and a lower alkoxy group]. The condensing reaction of the compound [IX] with the compound [X] can be carried out in the presence of a dehydrating agent and an acid acceptor. As the dehydrating agent, there may be suitably used dicyclohexylcarbodiimide, carbonyldiimidazole, 1-methyl-2-bromopyridinium iodide, or benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate. As the acid acceptor, there may be suitably used an organic base (e.g., triethylamine, diisopropylethylamine, pyridine, 4-(N,N-dimethylamino)pyridine, or 1,8-diazabiclo [5.4.0] undec-7-ene). The present reaction proceeds suitably at 0 to 120 °C, particularly 10 to 80 °C. On the other hand, the condensing reaction of the reactive derivative of the compound [IX] with the compound [X] can be carried out in the presence or absence of an acid acceptor. As the acid acceptor, there may be used an organic base (e.g., pyridine, triethylamine, N-methylpiperidine, N-methylmorpholine, N,N-diisopropyl-N-ethylamine, 4-(N,N-dimethylamino)pyridine, or 4-pyrrolinopyridine). The reaction proceeds suitably at 0 to 120°C, particularly 10 to 80 °C. The cleavage reaction of the oxazolidine ring can be carried out in the presence of an acid in a suitable solvent. As the acid, there may be used acids such as p-toluenesulfonic acid, camphorsulfonic acid, methanesulfonic acid and hydrochloric acid. As the solvent, there may be suitably used alcohol, particularly methanol. The present reaction proceeds suitably at -20 to 80 °C, particularly 0 to 30 °C. The removal of the protecting groups of the hydroxyl groups at the 7-position and the 10-position in the taxane skeleton can be carried out by a conventional method depending on the kind of protecting group. For example, when said protecting groups are 2,2,2-trichloroethoxycarbonyl groups, zinc-acetic acid may be used for removing them, and when said protecting groups are triethylsilyl groups, p-toluenesulfonic acid may be used for removing them. The removal of the protecting group R 5 from the compound obtained by the reaction of the compound [V] and the compound [VI], a salt thereof, or a reactive derivative thereof can be carried out by a conventional method depending on the kind of protecting group. For example, when said protecting group is a benzyl group, palladium-carbon in a suitable solvent, for example, tetrahydrofuran, may be used for removing it. The removal of the protecting group of the amino group at the β-position in a side chain at the 13-position in the compound [II] can be carried on by a conventional method depending on the kind of protecting group. For example, when said protecting group is a benzyloxycarbonyl group, palladium-carbon without a solvent or in suitable solvent, for example, tetrahydrofuran, may be used for removing it. The compound represented by the formula [II] in the present invention can be prepared by condensing a compound represented by the formula [XI]: wherein R 7 and R 8 represent lower alkyl groups, R 9 represents a protecting group, ring A is the same as defined above, or a reactive derivative thereof with the compound [X] in the same manner as the reaction of the compound [IX] or a reactive derivative thereof with the compound [X], then subjecting the resulting condensate to the steps of cleaving of the oxazolidine ring and removing the protecting group R 9 . In the compound [XI], as the protecting group R 9 , there may be mentioned conventional protecting groups such as the tert-butoxycarbonyl group. As the reactive derivative of the compound [XI], there may be mentioned the same reactive derivative of the compound [IX] such as an acid halide, an active ester, and a mixed acid anhydride. The cleavage reaction of the oxazolidine ring can be carried out in the presence of an acid. As the acid, there may be suitably used formic acid. The present reaction proceeds suitably at 0 to 50 °C, particularly 15 to 30 °C. Also, the compound [II] can be prepared by subjecting a compound represented by the formula [XII]: wherein R 1 , R 2 , R 3 , R 4 , and ring A are the same as defined above, to an azide introduction reaction using a metal azide to obtain a compound represented by the formula [XIII]: wherein R 1 , R 2 , R 3 , R 4 , and ring A are the same as defined above, and reducing the azide group of the compound [XIII]. The compound [XI] and the compound [IX] can be prepared, for example, as shown in the following reaction scheme. wherein R 10 represents an ester residue; Ts represents a p-toluenesulfonyl group; ring A is the same as defined above. The compound [XI] in which ring A is a cyclopropyl group can be prepared by dihydroxylating 3-cyclopropylacrylic acid ester [XXI] to obtain the compound [XX], eliminating the hydroxyl group at the 2-position to prepare 3-cyclopropyl-2-oxiranecarboxylic acid ester [XVIII], subjecting the compound to the azide-introduction reaction using a metal azide to obtain the compound [XVII], subjecting the resulting compound to a reduction reaction to the compound [XVI], protecting the amino group with R 9 , tert-butoxycarbonyl group, to obtain 3-tert-butoxycarbonylamino-2-hydroxy-3-cyclopropylpropionic acid ester [XV], subjecting the said compound to oxazolidine ring formation to obtain the compound [XIV], and hydrolysis of the compound [XIV]. The compound [XII] can be prepared by hydrolysis of the compound [XVIII] to obtain the compound represented by the formula [XXV]: wherein ring A is the same as defined above, reacting the compound [XXV] or a reactive derivative thereof with the compound [X] in the same manner as the reaction of the compound [IX] or a reactive derivative thereof with the compound [X]. As the reactive derivative of the compound [XXV], there may be mentioned the same reactive derivative of the compound [IX] such as an acid halide, an active ester, and a mixed acid anhydride. The compound [X] can be prepared by protecting hydroxyl groups at the 7-position and the 10-position in 10-deacetylbaccatin III by the method described in Japanese Provisional Patent Publications Nos. 305077/1988, 30479/1987, and Journal of American Chemical Society, Vol. 110, p.5917, (1988). The compound [IV] can be prepared be reacting a compound represented by the formula [VIII]: YOH wherein Y is the same as defined above, or a reactive derivative thereof with a compound represented by the formula [XXVI]: HZ(CH 2 ) n COOR 11 wherein R 11 represents a hydrogen atom or an ester residue; and Z and n are the same as defined above, and removing the ester residue, if necessary. The compound [XXII] can also be prepared by the hydrolysis of the substituted or unsubstituted cyclopropanecarbaldehyde acetals reported in Tetrahedron, Vol.42, p.6447-6458, (1986). In the present invention, as the C 1-6 alkyl group, there may be mentioned, for example, that having particularly 1 to 4 carbon atoms such as a methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, secondary butyl group, tertiary bytyl group, pentyl group, isopentyl group, neopentyl group, tertiary pentyl group, and hexyl group. As the C 2-7 alkanoyl group, there may be mentioned, for example, that having particularly 2 to 5 carbon atoms such as the acetyl group, propionyl group, butyryl group, valeryl group, and pivaloyl group. As the halogen atom, there may be mentioned chlorine, bromine, fluorine, and iodine. In the present specification, taxane or taxane skeleton means a diterpene skeleton represented by the following formula. Examples The present invention is illustrated in more detail by the following Examples. Example 1 (1)To a suspension of 85.8 g of methoxycarbonylmethylenetriphenylphosphorane in 550 ml of benzene is added dropwise a solution of 15.0 g of cyclopropanecarbaldehyde in 50 ml of benzene at room temperature under argon atmosphere. The mixture is stirred at 55 °C overnight. After the reaction mixture is cooled to room temperature, the reaction mixture is poured into 800ml of ice water. The aqueous mixture is extracted with 600 ml of chloroform twice. The chloroform layer is washed with brine. The organic layer is dried and evaporated under reduced pressure to remove the solvent. The residue is purified by silica gel column chromatography (solvent; hexane:ethyl acetate=12:1) to give 17.4 g of methyl trans-3-cyclopropylacrylate. Yield:65% MS(m/z):126(M + ) IR(neat,cm -1 ):1720,1660 NMR(CDCl 3 , δ ):0.60-0.68(2H,m), 0.91-0.99(2H,m), 1.51-1.64(1H,m), 3.71(3H,s), 5.90(1H,d,J=15Hz), 6.43(1H,dd,J=10,15Hz) (2)To a solution of 68.2 g of potassium ferricyanide and 28.6 g of potassium carbonate in 640 ml of tert-butanol-water (1 : 1) is added 0.537 g of 1,4-bis(9-O-dihydroquinidyl)phthalazine. The pH of the reaction mixture is adjusted to pH 10.9 with an aqueous solution of phosphoric acid. After a solution of osmium tetroxide in 0.35 ml of toluene (0.393M) is added to the mixture, the resulting mixture is stirred at room temperature for 30 minutes. Then, methyl trans-3-cyclopropylacrylate is added to the mixture, and the mixture is stirred for 24 hours. After the reaction mixture is cooled with ice, 106 g of sodium sulfite is added to the mixture. Then, the mixture is stirred for 30 minutes. The mixture is extracted with ethyl acetate four times. The organic layer is dried and the solvent is removed in vacuo. The residue is purified by silica gel column chromatography (solvent; hexane:ethyl acetate=3:1) to give 4.22 g of methyl (2S,3R)-3-cyclopropyl-2,3-dihydroxypropionate. Yield:38% m.p.:54-57°C [α] D 20 +42.7° (c=1,chloroform) FAB-MS(m/z):183(M + +Na) IR(nujol,cm -1 ):3440,1730 NMR(CDCl 3 , δ ):0.25-0.34(1H,m), 0.38-0.47(1H,m), 0.52-0.69(2H,m), 1.15-1.28(1H,m), 2.24(1H,d,J=7Hz), 3.12(1H,ddd,J=2,7,9Hz), 3.18(1H,d,J=6Hz), 3.82(3H,s), 4.25(1H,dd,J=2,6Hz). (3)Under argon atmosphere, a solution of 4.22 g of methyl (2S,3R)-3-cyclopropyl-2,3-dihydroxypropionate in 140 ml of methylene chloride is cooled to -3 °C. Then, 4.00 g of triethylamine and 5.17 g of p-toluenesulfonyl chloride are added to the mixture successively. The mixture is stirred for 3 days. Then, the solvent is removed in vacuo. The residue is poured into a mixture of ethyl acetate and water. The organic layer is washed with brine and dried. The solvent is removed in vacuo. The residue is purified by silica gel column chromatography (solvent; hexane:ethyl acetate=1:3) to give 6.54 g of methyl (2S,3R)-3-cyclopropyl-3-hydroxy-2-(p-toluenesulfonyloxy)propionate. Yield:79% m.p.:75-78°C MS(m/z):312(M + -2) IR(neat,cm -1 ):3520,1760 NMR(CDCl 3 , δ ):0.16-0.26(1H,m), 0.36-0.46(2H,m), 0.53-0.65(1H,m), 0.90-1.05(1H,m), 2.11(1H,d,J=7Hz), 2.45(3H,s), 3.26(1H,ddd,J=4,7,10Hz), 3.69(3H,s), 4.93(1H,d,J=4Hz), 7.32-7.38(2H,m), 7.82-7.88(2H,m). (4)To a solution of 2.97 g of methyl (2S,3R)-3-cyclopropyl-3-hydroxy-2-(p-toluenesulfonyloxy)propionate in 50 ml of acetonitrile are added 10.86 ml of water and 3.96 g of potassium carbonate successively at room temperature. Then, the reaction mixture is stirred at 50 °C for 2 days. The reaction mixture is cooled to room temperature, and insoluble materials are removed by filtration. The filtrate is concentrated under reduced pressure. The residue is purified by silica gel column chromatography (solvent; diethylether) to give methyl (2R,3R)-3-cyclopropyl-2,3-epoxypropionate quantitatively. MS(m/z):142(M + ) IR(neat,cm -1 ):1750 NMR(CDCl 3 , δ ):0.36-0.44(1H,m), 0.52-0.76(3H,m), 0.86-0.98(1H,m), 2.58(1H,dd,J=4,8Hz), 3.56(1H,d,J=4Hz), 3.83(3H,s). (5)To a solution of 2.89 g of methyl (2R,3R)-3-cyclopropyl-2,3-epoxypropionate in 112.5 ml of methanol-water (8:1) are added 14 ml of methyl formate and 16.60 g of sodium azide. Then, the reaction mixture is stirred at 50 °C overnight. The reaction mixture is cooled to room temperature and evaporated to remove methanol. The residue is dissolved in ethyl acetate. The solution is washed with brine and dried. The solvent is removed in vacuo. The residue is purified by silica gel column chromatography (solvent; hexane:ethyl acetate=4:1) to give 2.61 g of methyl (2R,3S)-3-cyclopropyl-3-azido-2-hydroxypropionate. Yield:70% [α] D 23 -67.19° (c=1,chloroform) FAB-MS(m/z):186(MH + ) IR(neat,cm -1 ):3480,2100,1740 NMR(CDCl 3 , δ ):0.29-0.39(1H,m), 0.50-0.59(1H,m), 0.63-0.73(1H,m), 0.80-0.90(1H,m), 1.37-1.51(1H,m), 2.83(1H,dd,J=2,10Hz), 3.06(1H,d,J=7Hz), 3.82(3H,s), 4.29(1H,dd,J=2,7Hz). (6)To a solution of 1.82 g of methyl (2R,3S)-3-cyclopropyl-3-azido-2-hydroxypropionate in 60 ml of ethyl acetate are added 600 mg of 10 % palladium-carbon and 2.57 g of t-butoxycarboxylic anhydride. The mixture is stirred under the atmospheric pressure of hydrogen at room temperature for one hour. The inorganic materials are removed by filtration, and the filtrate is condensed. The residue is purified by silica gel column chromatography (solvent; hexane:ethyl acetate=2:1) to give 2.78 g of methyl (2R,3S)-3-cyclopropyl-3-tert-butoxycarbonylamino-2-hydroxypropionate. Yield:100% m.p.:93°C [α] D 23 -59.79° (c=1,chroloform) FAB-MS(m/z):260(MH + ) IR(nujol,cm -1 ):3520,3440,3320,1740,1720,1710,1690 NMR(CDCl 3 , δ ):0.32-0.39(1H,m), 0.41-0.51(1H,m), 0.51-0.62(2H,m), 1.07-1.21(1H,m), 1.41(9H,s), 3.19(1H,d,J=5Hz), 3.29(1H,dt,J=2,10Hz), 3.78(3H,s), 4.31(1H,dd,J=2,5Hz), 4.90(1H,dlike). (7)To a solution of 2.63 g of methyl (2R,3S)-3-cyclopropyl-3-tert-butoxycarbonylamino-2-hydroxypropionate in 60 ml of benzene are added 1.94 ml of isopropenylmethylether and 0.25 g of p-toluenesulfonic acid pyridinium salt. The mixture is stirred at room temperature for one hour, and then refluxed for 40 minutes. After the mixture is cooled, 1.94 ml of isopropenylmethylether is added to the reaction mixture. The mixture is stirred at room temperature for 10 minutes, refluxed for 40 minutes, and evaporated to remove the solvent. The residue is purified by silica gel column chromatography (solvent; hexane:ethyl acetate=8:1) to give 2.69 g of methyl (4S,5R)-3-tert-butoxycarbonyl-2,2-dimethyl-4-cyclopropyl-5-oxazolidinecarboxylate. Yield:89% MS(m/z):299(M + ) IR(neat,cm -1 ):1760,1720,1700 NMR(CDCl 3 , δ ):0.23-0.33(1H,m), 0.43-0.54(1H,m), 0.61-0.76(2H,m), 1.10-1.22(1H,m), 1.49(9H,s), 1.62(3H,s), 1.64(3H,s), 3.73-3.88(1H,m), 3.77(3H,s), 4.42(1H,d,J=2.0Hz). (8)To a solution of 2.66 g of methyl (4S,5R)-3-tert-butoxycarbonyl-2,2-dimethyl-4-cyclopropyl-5-oxazolidinecarboxylate in 60 ml of methanol is added dropwise a solution of 255 mg of lithium hydroxide in 30 ml of water under ice-cooling. The reaction mixture is warmed to room temperature, stirred for one hour and evaporated under reduced pressure to remove methanol. Chloroform is added to the residue. The pH of the mixture is adjusted to about pH 2 with 10 % hydrochloric acid under ice-cooling thereto. The chloroform layer is washed with brine, dried, and evaporated under reduced pressure to remove the solvent to give 2.65 g of (4S,5R)-3-tert-butoxycarbonyl-2,2-dimethyl-4-cyclopropyl-5-oxazolidinecarboxylic acid. Yield:100% m.p.:104-108°C FAB-MS(m/z):286(MH + ) IR(nujol,cm -1 ):3080,1720,1690 NMR(CDCl 3 , δ ):0.27-0.38(1H,m), 0.45-0.56(1H,m), 0.62-0.76(2H,m), 1.11-1.24(1H,m), 1.49(9H,s), 1.65(3H,s), 1.66(3H,s), 3.75-3.88(1H,m), 4.45(1H,d,J=2Hz), 6.60(1H,brs). (9-1)To a solution of 1.20 g of (4S,5R)-3-tert-butoxycarbonyl-2,2-dimethyl-4-cyclopropyl-5-oxazolidinecarboxylic acid and 2.5 g of 4α-acetoxy-2α-benzoyloxy-5β,20-epoxy-1β,13α-dihydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one in 60 ml of toluene are added 922 mg of 1,3-dicyclohexylcarbodiimide and 171 mg of 4-dimethylaminopyridine. The mixture is stirred at 80 °C for 90 minutes. Insoluble materials are removed from the reaction mixture by filtration, and the filtrate is evaporated in vacuo. The residue is purified by silica gel column chromatography (solvent; hexane:ethyl acetate=3:1) to give 3.1 g of 4α-acetoxy-2α-benzoyloxy-13α-[(4S,5R)-3-tert-butoxycarbonyl-2,2-dimethyl-4-cyclopropyloxazolidin-5-ylcarbonyloxy]-5ß,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one. Yield:96% FAB-MS(m/z):1162(MH + ) IR(nujol,cm -1 ):3500,1760,1740,1700 NMR(CDCl 3 , δ ):0.23-0.33(1H,m), 0.45-0.57(1H,m), 0.64-0.80(2H,m), 1.08-1.18(1H,m), 1.20(3H,s), 1.27(3H,s), 1.50(9H,s), 1.58(3H,s), 1.66(6H,s), 1.71(1H,s), 1.85(3H,s), 2.00-2.14(1H,m), 2.08(3H,d,J=1Hz), 2.24-2.33(2H,m), 2.42(3H,s), 2.64(1H,ddd,J=7,10,14Hz), 3.90-3.95(1H,m), 3.97(1H,d,J=7Hz), 4.17(1H,d,J=8Hz), 4.35(1H,d,J=8Hz), 4.45(1H,d,J=2Hz), 4.60(1H,d,J=12Hz), 4.75(1H,d,J=12Hz), 4.80(1H,d,J=12Hz), 4.92(1H,d,J=12Hz), 4.95-5.01(1H,m), 5.61(1H,dd,J=7,11Hz), 5.70(1H,d,J=7Hz), 6.18-6.26(1H,m), 6.27(1H,s), 7.46-7.54(2H,m), 7.60-7.67(1H,m), 8.06-8.12(2H,m). (9-2)To a solution of 85.5 mg of (4S,5R)-3-tert-butoxycarbonyl-2,2-dimethyl-4-cyclopropyl-5-oxazolidinecarboxylic acid in 1 ml of toluene are added under argon atmosphere 44 µl of triethylamine and 38.4 mg of 4-(N,N-dimethylamino)pyridine at 0 °C. A solution of 76.7 mg of 2,4,6-trichlorobenzoyl chloride in 1 ml of toluene is added to the mixture. The mixture is stirred at room temperature for 1 hour. Then, to the mixture is added 171.2 mg of 4α-acetoxy-2α-benzoyloxy-5β-20-epoxy-1β,13α-dihydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one, and the mixture is continued to be stirred at the same temperature for 2 hours. The reaction mixture is diluted with ethyl acetate, washed with 1 % hydrochloric acid, saturated aqueous sodium hydrogen carbonate solution, water, and brine in this order and dried over sodium sulfate. The solvent is removed in vacuo. The residue is purified by silica gel column chromatography (solvent; n-hexane : ethyl acetate= 3 : 2) to give 183 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(4S,5R)-3-tert-butoxycarbonyl-2,2-dimethyl-4- cyclopropyloxazolidin-5-ylcarbonyloxy]-5β-20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one. The physical properties of the product are the same as those of the compound of Example 1(9-1). (10)A solution of 3.04 g of 4α-acetoxy-2α-benzoyloxy-13α-[(4S,5R)-3-tert-butoxycarbonyl-2,2-dimethyl-4-cyclopropyloxazolidin-5-ylcarbonyloxy]-5β,20-epoxy-1 β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one in 50 ml of formic acid is stirred at room temperature for 2 hours. After formic acid is removed in vacuo, the reaction mixture is crystallized from ethanol-diisopropylether. Crystals are collected by filtration, washed with diisopropylether and then dried to give 2.54 g of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-amino-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one formate. Yield:91% m.p.:154-172°C(decomposed) FAB-MS(m/z):1022(MH + ) IR(nujol,cm -1 ):3440,1760,1720 NMR(CDCl 3 , δ ):0.28-0.40(1H,m), 0.43-0.57(1H,m), 0.57-0.78(2H,m), 1.10-1.15(1H,m), 1.18(3H,s), 1.23(3H,s), 1.84(3H,s), 2.00-2.12(1H,m), 2.04(3H,s), 2.24-2.32(2H,m), 2.39(3H,s), 2.55-2.69(1H,m), 2.69-2.78(1H,m), 3.90(1H,d,J=7Hz), 4.16(1H,d,J=8Hz), 4.20-4.62(5H,m), 4.33(1H,d,J=8Hz), 4.48(1H,d,J=6Hz), 4.59(1H,d,J=12Hz), 4.77(2H,slike), 4.87(1H,d,J=12Hz), 4.94-5.00(1H,m), 5.53(1H,dd,J=7,11Hz), 5.69(1H,d,J=7Hz), 6.20-6.29(1H,m), 6.23(1H,s), 7.45-7.53(2H,m), 7.57-7.66(1H,m), 8.03-8.10(2H,m), 8.32(1H,brs). (11)To a solution of 600 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-amino-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one formate in 15 ml of tetrahydrofuran are added dropwise a solution of 169 mg of potassium bicarbonate and 245 mg of tert-butoxycarboxylic anhydride in 5 ml of tetrahydrofuran. The mixture is stirred for 2.5 hours at room temperature. Inorganic materials are removed by filtration. Ethyl acetate is added to the filtrate. The mixture is washed with a saturated aqueous sodium bicarbonate solution, water and brine and dried. The solvent is removed in vacuo. The residue is purified by silica gel column chromatography (solvent; hexane:ethyl acetate=2:1) to give 471 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-tert-butoxycarbonylamino-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one. Yield:75% FAB-MS(m/z):1122(MH + ) IR(nujol,cm -1 ):3440,1760,1720 NMR(CDCl 3 , δ ):0.24-0.32(1H,m), 0.43-0.52(1H,m), 0.61-0.70(2H,m), 1.18-1.32(1H,m), 1.20(3H,s), 1.27(3H,s), 1.34(9H,s), 1.71(3H,s), 1.86(3H,s), 2.02(3H,d,J=1Hz), 2.05-2.13(1H,m), 2.30-2.38(2H,m), 2.39(3H,s), 2.64(1H,ddd,J=7,10,14Hz), 3.31(1H,dt,J=2,9Hz), 3.34(1H,d,J=6Hz), 3.91(1H,d,J=7Hz), 4.18(1H,d,J=8Hz), 4.34(1H,d,J=8Hz), 4.40(1H,dd,J=2,6Hz), 4.60(1H,d,J=12Hz), 4.75(1H,d,J=12Hz), 4.80(1H,d,J=12Hz), 4.88-4.93(1H,m), 4.91(1H,d,J=12Hz), 4.98(1H,d,J=8Hz), 5.56(1H,dd,J=7,11Hz), 5.71(1H,d,J=7Hz), 6.11-6.20(1H,m), 6.26(1H,s), 7.47-7.54(2H,m), 7.59-7.66(1H,m), 8.08-8.13(2H,m). (12)To a solution of 181 mg of ((3S)-3-benzyloxycarbonylamino-3-ethoxycarbonylpropionyloxy)acetic acid and 479 mg of 4α-acetoxy-2α-benzoyloxy-13α -[(2R,3S)-3-tert-butoxycarbonylamino-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one in 20 ml of tetrahydrofuran are added 106 mg of 1,3-dicyclohexylcarbodiimide and 5.2 mg of 4-dimethylaminopyridine. The mixture is stirred at 60 °C for 2 hours. Insoluble materials are removed by filtration, and the filtrate is evaporated under reduced pressure. The residue is purified by silica gel column chromatography (solvent; chloroform: methanol=60:1), and then silica gel column chromatography (solvent; hexane:ethyl acetate=2:1) to give 496 mg of 4α-acetoxy-2α-benzoyloxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-[(3S)-3-benzyloxycarbonylamino-3-ethoxycarbonylpropionyloxyacetoxy]-3-cyclopropylpropionyloxy}-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one. Yield:80% m.p.:107-121°C(decomposed) FAB-MS(m/z):1479(MH + +Na) IR(nujol,cm -1 ):3380,1760,1720 NMR(CDCl 3 , δ ):0.20-0.26(1H,m), 0.46-0.51(1H,m), 0.61-0.67(2H,m), 1.06-1.08(1H,m), 1.19(3H,s), 1.24(3H,s), 1.25-1.30(3H,m), 1.32(9H,s), 1.69(1H,s), 1.85(3H,s), 2.04(3H,s), 2.05-2.10(1H,m), 2.23-2.35(2H,m), 2.37(3H,s), 2.58-2.67(1H,m), 2.96-3.04(1H,m), 3.13-3.21(1H,m), 3.55-3.62(1H,m), 3.91(1H,d,J=7Hz), 4.17(1H,d,J=8Hz), 4.19-4.28(2H,m), 4.34(1H,d,J=8Hz), 4.58(1H,d,J=12Hz), 4.64-4.70(1H,m), 4.73(1H,d,J=16Hz), 4.74(1H,d,J=16Hz), 4.74(1H,d,J=12Hz), 4.78(1H,d,J=12Hz), 4.85(1H,d,J=16Hz), 4.89(1H,d,J=12Hz), 4.98(1H,dlike,J=9Hz), 5.09-5.21(5H,m), 5.56(1H,dd,J=7,11Hz), 5.70(1H,d,J=7Hz), 5.81(1H,dlike,J=8Hz), 6.12-6.19(1H,m), 6.25(1H,s), 7.29-7.38(5H,m), 7.50(2H,tlike), 7.62(1H,t,J=7Hz), 8.10(2H,d,J=7Hz). (13)To a solution of 262 mg of 4α-acetoxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-[(3S)-3-benzyloxycarbonylamino-3-ethoxycarbonylpropionyloxyacetoxy]-3-cyclopropylpropionyloxy}-2α-benzoyloxy-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one in a mixture of 20 ml of methanol and 4 ml of acetic acid is added 352 mg of zinc powder. The mixture is stirred at 60 °C for 30 minutes. Inorganic materials are removed by filtration, and the filtrate is evaporated under reduced pressure. The residue is extracted with ethyl acetate by adding ethyl acetate and water. The extract is washed with 1 % hydrochloric acid, water and a saturated aqueous sodium successively, and the solvent is removed in vacuo. The residue is purified by silica gel column chromatography (solvent; chloroform: methanol=50:1) to give 155 mg of 4α-acetoxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-[(3S)-3-benzyloxycarbonylamino-3-ethoxycarbonylpropionyloxyacetoxy]-3-cyclopropylpropionyloxy}-2α-benzoyloxy-5β,20-epoxy-1β,7β,10β-trihydroxytax-11-en-9-one. Yield:78% FAB-MS(m/z):1107(MH + ) IR(nujol,cm -1 ):3400,1750,1700 NMR(CDCl 3 , δ ):0.20-0.28(1H,m), 0.43-0.52(1H,m), 0.58-0.66(2H,m), 0.97-1.07(1H,m), 1.12(3H,s), 1.20(3H,s), 1.27(3H,t,J=7Hz), 1.32(9H,s), 1.60-1.73(1H,m), 1.68(1H,s), 1.75(3H,s), 1.79-1.90(1H,m), 1.92(3H,brs), 2.15-2.28(2H,m), 2.31(3H,s), 2.52-2.66(1H,m), 2.99(1H,dd,J=4,17Hz), 3.19(1H,dd,J=4,17Hz), 3.55-3.66(1H,m), 3.90(1H,d,J=7Hz), 4.15-4.28(5H,m), 4.31(1H,d,J=8Hz), 4.64-4.83(3H,m), 4.78(2H,d,J=8Hz), 4.93-4.99(1H,m), 5.08-5.17(1H,m), 5.14(2H,slike), 5.18-5.27(2H,m), 5.68(1H,d,J=7Hz), 5.88-5.97(1H,m), 6.11-6.21(1H,m), 7.30-7.38(5H,m), 7.46-7.53(2H,m), 7.57-7.65(1H,m), 8.07-8.14(2H,m). (14)To a solution of 243 mg of 4α-acetoxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-[(3S)-3-benzyloxycarbonylamino-3-ethoxycarbonylpropionyloxyacetoxy]-3-cyclopropyl-propionyloxy}-2α-benzoyloxy-5β,20-epoxy-1β,7β,10β-trihydroxytax-11-en-9-one in 35 ml of tetrahydrofuran are added 150 mg of 10 % palladium-carbon and 0.032 mg of methanesulfonic acid. The mixture is stirred under the atmospheric pressure of hydrogen at room temperature for 45 minutes. Inorganic materials are removed by filtration, and the filtrate is removed in vacuo. Diethylether is added to the residue to precipitate crystals. Crystals are collected by filtration, washed with diethylether, and dried to give 174 mg of 4α-acetoxy-2α-benzoyloxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-[(3S)-3-amino-3-ethoxycarbonylpropionyloxyacetoxy]-3-cyclopropylpropionyloxy}-5β,20-epoxy-1β,7β,10β-trihydroxytax-11-en-9-one methanesulfonate. Yield:74% m.p.:151°C(decomposed) FAB-MS(m/z):973(MH + ) IR(nujol,cm -1 ):3400,1740,1700 NMR(DMSO-d 6 , δ ):0.20-0.30(1H,m), 0.32-0.42(1H,m), 0.48-0.57(2H,m), 1.00-1.06(1H,m), 1.02(3H,s), 1.04(3H,s), 1.24(3H,t,J=7Hz), 1.35(9H,s), 1.55(3H,s), 1.60-1.75(1H,m), 1.79(3H,s), 2.18-2.29(3H,m), 2.31(6H,s), 3.04(1H,dd,J=6,18Hz), 3.11(1H,dd,J=6,18Hz), 3.37-3.48(1H,m), 3.75(1H,d,J=7Hz), 4.02-4.13(3H,m), 4.16-4.28(2H,m), 4.40(1H,t,J=6Hz), 4.65(1H,s), 4.90(2H,s), 4.92-4.98(2H,m), 5.03(1H,d,J=7Hz), 5.07(1H,d,J=4Hz), 5.14(1H,s), 5.47(1H,d,J=7Hz), 5.90-6.00(1H,m), 7.18(1H,d,J=9Hz), 7.52-7.60(2H,m), 7.63-7.71(1H,m), 7.98-8.05(2H,m), 8.38(3H,brs). Example 2 To a solution of 818 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-tert-butoxycarbonylamino-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one obtained in Example 1(11) in a mixture of 75 ml of methanol and 15 ml of acetic acid is added 1.43 g of zinc powder. The mixture is stirred at 60 °C for 30 minutes. After the reaction mixture is cooled to room temperature, insoluble materials are removed by filtration, and the filtrate is evaporated in vacuo. To the residue is added a mixture of ethyl acetate and water. The organic layer is washed with cold 1 % hydrochloric acid, water, saturated sodium bicarbonate and brine and. The solvent is removed in vacuo. The residue is purified by silica gel column chromatography (solvent; chloroform:methanol=30:1) to give 512 mg of crude crystals. The crude crystals are washed with a mixture of diisopropylether-hexane and dried to give 476 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-tert-butoxycarbonylamino-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β,7β,10β-trihydroxytax-11-en-9-one. Yield:85% m.p.:173-179°C [α] D 22 -55.59° (c=1,chloroform) FAB-MS(m/z):772(MH + ) IR(nujol,cm-1):3400,1700 NMR(CDCl 3 , δ ):0.23-0.32(1H,m), 0.42-0.52(1H,m), 0.59-0.68(2H,m), 1.13(3H,s), 1.19-1.29(1H,m), 1.23(3H,s), 1.33(9H,s), 1.58-1.67(1H,m), 1.69(1H,s), 1.75(3H,s), 1.79-1.91(1H,m), 1.93(3H,d,J=1Hz), 2.29(2H,d,J=9Hz), 2.37(3H,s), 2.59(1H,ddd,J=7,10,14Hz), 3.32(1H,dt,J=2,9Hz), 3.46(1H,d,J=6Hz), 3.92(1H,d,J=7Hz), 4.19(1H,d,J=8Hz), 4.2-4.3(1H,m), 4.21(1H,d,J=2Hz), 4.34(1H,d,J=8Hz), 4.39(1H,dd,J=2,6Hz), 4.90-5.00(2H,m), 5.22(1H,d,J=2Hz), 5.69(1H,d,J=7Hz), 6.12-6.22(1H,m), 7.46-7.54(2H,m), 7.57-7.65(1H,m), 8.07-8.13(2H,m). Example 3 (1)A solution of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-amino-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one formate obtained in Example 1(10) in ethyl acetate is treated with saturated aqueous sodium bicarbonate solution to give 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-amino-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxy-carbonyloxy)tax-11-en-9-one. To a solution of 504 mg of the resulting free base in methylene chloride is added 73 mg of t-butylisocyanate at room temperature under argon atmosphere, and the mixture is stirred overnight. Water is added to the reaction mixture, and the mixture is extracted with chloroform. The extract is washed with brine, dried, and evaporated under reduced pressure to remove the solvent. The residue is purified by silica gel column chromatography (solvent; hexane:ethyl acetate=3:1) to give 376 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-tert-butylaminocarbonylamino-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one. Yield:68% m.p.:167-174°C FAB-MS(m/z):1143(M + +Na) IR(nujol,cm -1 ):3400,1760,1720,1660 NMR(CDCl 3 , δ ):0.24-0.31(1H,m), 0.41-0.50(1H,m), 0.54-0.70(2H,m), 1.19-1.28(7H,m), 1.24(9H,s), 1.76(1H,s), 1.86(3H,s), 2.00-2.12(1H,m), 2.03(3H,d,J=1Hz), 2.25-2.49(2H,m), 2.41(3H,s), 2.63(1H,ddd,J=7,10,14Hz), 3.35-3.45(1H,ddlike,J=2,9Hz), 3.75(1H,d,J=7Hz), 3.91(1H,d,J=7Hz), 4.18(1H,d,J=8Hz), 4.26(1H,brs), 4.37(1H,d,J=8Hz), 4.39(1H,dd,J=2,7Hz), 4.53(1H,d,J=9Hz), 4.60(1H,d,J=12Hz), 4.75(1H,d,J=12Hz), 4.80(1H,d,J=12Hz), 4.91(1H,d,J=12Hz), 4.95-5.01(1H,dlike), 5.56(1H,dd,J=7,11Hz), 5.72(1H,d,J=7Hz), 6.10-6.19(1H,m), 6.26(1H,s), 7.47-7.55(2H,m), 7.59-7.67(1H,m), 8.07-8.13(2H,m). (2)A 355 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-tert-butylaminocarbonylamino-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one is treated in the same manner as described in Example 1(12)-(14) to give 158 mg of 4α-acetoxy-13α-{(2R,3S)-3-tert-butylaminocarbonylamino-2-[(3S)-3-amino-3-ethoxycarbonylpropionyloxy)acetoxy]-3-cyclopropylpropionyloxy}-2α-benzoyloxy-5β,20-epoxy-1β,7β,10β-trihydroxytax-11-en-9-one methanesulfonate. Yield:80% m.p.:165-169°C FAB-MS(m/z):972(MH + ) IR(nujol,cm -1 ):3400,1750,1660 NMR(DMSO-d 6 , δ ):0.08-0.17(1H,m), 0.28-0.37(1H,m), 0.46-0.53(2H,m), 0.97-1.08(1H,m), 1.03(6H,brs), 1.15(9H,brs), 1.23(3H,t,J=7Hz), 1.54(3H,s), 1.61-1.72(1H,m), 1.78(3H,s), 2.21-2.36(3H,m), 2.32(3H,s), 2.33(3H,s), 3.04(1H,dd,J=6,18Hz), 3.12(1H,dd,J=6,18Hz), 3.74(1H,d,J=7Hz), 3.75-3.81(1H,m), 4.01-4.13(3H,m), 4.15-4.28(2H,m), 4.40(1H,t,J=6Hz), 4.62(1H,s), 4.90-5.00(2H,m), 4.90(1H,d,J=16Hz), 4.96(1H,d,J=16Hz), 5.05(1H,d,J=7Hz), 5.10(1H,d,J=3Hz), 5.14(1H,brs), 5.47(1H,d,J=7Hz), 5.75(1H,brs), 5.88-5.98(2H,m), 7.53-7.61(2H,m), 7.63-7.71(1H,m), 8.01-8.07(2H,m), 8.35(3H,brs). Example 4 (1-1)To a solution of 500 mg of ethyl (2R,3R)-3-cyclopropyl-2,3-epoxypropionate in 20 ml of tetrahydrofuran is added dropwise 3.52 ml of 1N sodium hydroxide under ice-cooling. The reaction mixture is stirred at room temperature for 2.5 hours. After the reaction mixture is concentrated under reduced pressure, the residue is diluted with 20 ml of water. The reaction mixture is washed with diethylether. The aqueous layer is cooled in an ice-bath. Then, 508 mg of 4-dimethylaminopyridine hydrochloride is added to the mixture. After the resulting mixture is stirred at room temperature for one hour, the reaction mixture is purified by non-ionic absorbing resin HP-20 (Mitsubishi Kasei Kogyo Ltd.) and aqueous eluate is lyophilized to give 503 mg of 4-dimethylaminopyridinium (2R,3R)-3-cyclopropyl-2,3-epoxypropionate. A suspension of 38 mg of 4-dimethylaminopyridinium (2R,3R)-3-cyclopropyl-2,3-epoxypropionate, 45 mg of 4α-acetoxy-2α-benzoyloxy-5β,20-epoxy-1β,13α-dihydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one and 31 mg of 1,3-dicyclohexylcarbodiimide in 1 ml of toluene is stirred at 50°C for one hour. The reaction mixture is cooled to room temperature and diluted with diethylether, and insoluble materials are removed by filtration. The filtrate is washed with brine, dried and evaporated to remove the solvent. The residue is purified by thin layer chromatography (solvent; hexane:ethyl acetate=3:2) to give 45 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3R)-3-cyclopropyl-2,3-epoxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one. Yield:90% FAB-MS(m/z:):1025(M + +Na), 1027([M + +Na]+2), 1029([M + +Na]+4) IR(nujol,cm -1 ):3480,1760,1720 NMR(300MHz, CDCl 3 , δ ):0.42(1H,m), 0.66(2H,m), 0.81(1H,m), 0.95(1H,m), 1.20(3H,s), 1.26(3H,s), 1.70(1H,s,D 2 Oexch), 1.86(3H,s), 2.05-2.1(1H,m), 2.09(3H,d,J=1Hz), 2.25-2.35(2H,m), 2.39(3H,s), 2.63(1H,dd,J=4,9Hz), 2.64(1H,m), 3.69(1H,d,J=4Hz), 3.96(1H,d,J=7Hz), 4.17(1H,d,J=9Hz), 4.35(1H,d,J=9Hz), 4.61(1H,d,J=12Hz), 4.78(1H,d,J=12Hz), 4.91(1H,d,J=12Hz), 4.98(1H,m), 5.59(1H,dd,J=7,11Hz), 5.69(1H,d,J=7Hz), 6.27(1H,s), 6.31(1H,m), 7.49(2H,m), 7.63(1H,m), 8.08(2H,m). (1-2)A 2.04 g of benzyl (2R,3R)-3-cyclopropyl-2,3-epoxypropionate is dissolved in 40 ml of tetrahydrofuran and subjected to catalytic hydrogenation at room temperature under atmospheric pressure using 1 g of 10 % palladium-carbon. After 2 hours, the catalyst is removed by filtration. After 40 ml of toluene is added to the filtrate, the resulting mixture is concentrated under reduced pressure to remove tetrahydrofuran to give a solution of (2R,3R)-3-cyclopropyl-2,3-epoxypropionic acid in toluene. Then, 2.74 g of 4α-acetoxy-2α-benzoyloxy-5β,20-epoxy-1β,13α-dihydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one, 1.89 g of 1,3-dicyclohexylcarbodiimide and 187 mg of 4-dimethylaminopyridine are added to the resulting solution of (2R,3R)-3-cyclopropyl-2,3-epoxypropionic acid in toluene. The mixture is stirred at 80 °C for one hour. The reaction mixture is cooled to room temperature and treated in the same manner as described in Example 4(1-1). The residue is purified by silica gel frash column chromatography (solvent; ethyl acetate:hexane=1:2) to give 3.02 g of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3R)-3-cyclopropyl-2,3-epoxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one. The physical properties of the product are the same as those of the compound of Example 4(1-1). (2-1)To a solution of 108 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3R)-3-cyclopropyl-2,3-epoxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one in 3 ml of methanol-water (8:1) and 0.3 ml of methyl formate is added 211 mg of sodium azide. The reaction mixture is stirred at 50 °C for 15 hours. The reaction mixture is cooled to room temperature, poured into ice-water, and extracted with ethyl acetate. The organic layer is washed with brine, dried and evaporated to remove the solvent. The residue is purified by thin layer chromatography (solvent; chloroform:ethyl acetate=10:1) to give 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-azide-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one. Yield:80% FAB-MS(m/z):1068(M + +Na), 1070([M + +Na]+2), 1072([M + +Na]+4) IR(nujol,cm -1 ):3500,2110,1760,1720 NMR(300MHz, CDCl 3 , δ ):0.35(1H,m), 0.62(1H,m), 0.71 (1H,m), 0.91(1H,m), 1.21(3H,s), 1.28(3H,s), 1.47(1H,m), 1.74(1H,s,D 2 Oexch), 1.87(3H,s), 2.08(1H,m), 2.12(3H,d,J=1Hz), 2.2-2.3(2H,m), 2.36(3H,s), 2.65(1H,m), 3.05(1H,dd,J=2,10Hz), 3.11(1H,d,J=8Hz,D 2 Oexch), 3.93(1H,d,J=7Hz), 4.18(1H,d,J=8Hz), 4.34(1H,d,J=8Hz), 4.39(1H,dd,J=2,8Hz), 4.61(1H,d,J=12Hz), 4.76(1H,d,J=12Hz), 4.81(1H,d,J=12Hz), 4.92(1H,d,J=12Hz), 4.98(1H,m), 5.57(1H,dd,J=7,11Hz), 5.70(1H,d,J=7Hz), 6.22(1H,m), 6.28(1H,s), 7.49(2H,m), 7.63(1H,m), 8.07(2H,m). (2-2)To a solution of 55 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3R)-3-cyclopropyl-2,3-epoxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one in 0.5 ml of tetra(n-butyl)tin azide is added a catalytic amount of zinc iodide. The reaction mixture is stirred at 50 °C. After 19 hours, the reaction mixture is cooled to room temperature and purified by silica gel frash column chromatography (solvent; chloroform:ethyl acetate=20:1) and thin layer chromatography (solvent; chloroform:ethyl acetate=10:1) to give 51 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-azide-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one. The physical properties of the product are the same as those of the compound of Example 4(2-1). (3-1)To a solution of 69 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-azide-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one in 3 ml of tetrahydrofuran is added 13 mg of platinum oxide. The reaction mixture is subjected to catalytic hydrogenation at room temperature under atmospheric pressure for 3 hours. After the catalyst is removed by filtration. Then, 0.1 ml of formic acid is added to the filtrate, and the mixture is evaporated to remove the solvent. To the residue is added methanol, and insoluble materials are removed by filtration. Then, the filtrate is evaporated to remove the solvent. The residue is washed to give 46 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-amino-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one formate. The physical properties of the product are the same as those of the compound of Example 1(10). (3-2)To a solution of 314 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-azide-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one in 12 ml of methanol are added 157 mg of 10 % palladium-carbon and 305 ml of 1N hydrochloric acid. The mixture is subjected to catalytic hydrogenation at room temperature under atmospheric pressure. After 1.5 hours, the catalyst is removed by filtration. The filtrate is evaporated to remove the solvent. Diisopropylether is added to the residue, and the resulting solid materials are collected by filtration to give 289 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-amino-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one hydrochloride. Yield:91% FAB-MS(m/z):1022(MH + +2) IR(nujol,cm -1 ):3410,3140,1760,1740,1730,1710 NMR(DMSO-d 6 , δ ):0.20-0.27(1H,m), 0.56-0.59(2H,m), 0.64-0.68(1H,m), 1.03(3H,s), 1.07-1.10(1H,m), 1.13(3H,s), 1.72(3H,s), 1.84-1.92(1H,m), 1.99(3H,s), 2.21(1H,dd,J=9,15Hz), 2.32-2.37(1H,m), 2.37(3H,s), 2.56-2.62(1H,m), 3.81(1H,d,J=7Hz), 4.08-4.15(3H,m), 4.44(1H,brdd,J=6,7Hz), 4.79(1H,d,J=12Hz), 4.95(1H,d,J=12Hz), 4.97(1H,d,J=12Hz), 5.03(1H,d,J=12Hz), 5.05(1H,d,J=10Hz), 5.11(1H,s), 5.48(1H,dd,J=7,11Hz), 5.52(1H,d,J=7Hz), 6.10(1H,brt,J=9Hz), 6.16(1H,s), 6.94(1H,d,J=5Hz), 7.57(2H,brt,J=8Hz), 7.69(1H,brt,J=7Hz), 7.99(2H,brd,J=7Hz), 8.28(3H,brs). (4)4α-Acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-amino-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one formate is treated in the same manner as described in Example 1(11) to give 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-tert-butoxycarbonylamino-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one. The physical properties of the product are the same as those of the compound of Example 1(11). (5)To a solution of 861 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-tert-butoxycarbonylamino-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one in 40 ml of tetrahydrofuran are added 321 mg of benzyloxy acetic acid, a solution of 404 mg of 1,3-dicyclohexylcarbodiimide in 10 ml of tetrahydrofuran and 9 mg of 4-dimethylaminopyridine. The reaction mixture is stirred at room temperature for 1.5 hours and condensed. The residue is dissolved in diethylether, and insoluble materials are removed by filtration. The filtrate is washed, dried and evaporated to remove the solvent. The residue is purified by silica gel frash column chromatography (solvent; hexane:ethyl acetate=3:1) to give 650 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-tert-butoxycarbonylamino-3-cyclopropyl-2-benzyloxyacetoxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one. Yield:67% ESI-MS(m/z):1292(M+Na + +2), 1290(M+Na + ) IR(nujol,cm -1 ):3444,1760,1725 NMR(CDCl 3 , δ ):0.22-0.26(1H,m), 0.45-0.51(1H,m), 0.60-0.67(2H,m), 1.03-1.11(1H,m), 1.19(3H,s), 1.26(3H,s), 1.33(9H,s), 1.70(1H,s), 1.85(3H,s), 2.02-2.11(1H ,m), 2.07(3H,J=1Hz), 2.29-2.34(2H,m), 2.39(3H,s), 2.65(1H,ddd,J=14,9,7Hz), 3.59(1H,dt,J=10,2Hz), 3.93(1H,d,J=7Hz), 4.17(1H,d,J=9Hz), 4.25(1H,d,J=17Hz), 4.31(1H,d,J=17Hz), 4.35(1H,d,J=1Hz), 4.60(1H,d,J=12Hz), 4.69(2H,s), 4.75(1H,d,J=12Hz), 4.79(1H,d,J=12Hz), 4.86-4.89(1H,m), 4.92(1H,d,J=12Hz), 4.99(1H,d,J=8Hz), 5.20(1H,d,J=2.0Hz), 5.58(1H,dd,J=7,11Hz), 5.71(1H,d,J=7Hz), 6.15-6.21(1H,m), 6.26(1H,s), 7.32-7.40(5H,m), 7.51(2H,t,J=8Hz), 7.63(1H,tt,J=1,7Hz), 8.11(2H,brdd,J=2,9Hz). (6)To a solution of 129 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-tert-butoxycarbonylamino-3-cyclopropyl-2-benzyloxyacetoxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one in 9 ml of tetrahydrofuran-acetic acid (1:2) is added 271 mg of 10 % palladium-carbon. The reaction mixture is subjected to catalytic hydrogenation at room temperature under atmospheric pressure for 2.5 hours. After the catalyst is removed by filtration, the filtrate is evaporated to remove the solvent. The residue is dissolved in ethyl acetate, washed with brine, dried and evaporated to remove the solvent. The residue is purified by silica gel frash column chromatography (solvent; hexane:ethyl acetate=2:1) to give 75 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-tert-butoxycarbonylamino-3-cyclopropyl-2-hydroxyacetoxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one. Yield:63% ESI-MS(m/z):1202(M+Na + +2), 1200(M+Na + ) IR(nujol,cm -1 ):3445,1756,1725 NMR(CDCl 3 , δ ):0.22-0.29(1H,m), 0.47-0.53(1H,m), 0.63-0.67(2H,m), 1.02-1.12(1H,m), 1.23(3H,s), 1.25(3H,s), 1.34(9H,s), 1.72(1H,s), 1.85(3H,s), 2.02-2.11(1H,m), 2.06(3H,d,J=1Hz), 2.27-2.36(2H,m), 2.39(3H,s), 2.45(1H,brt,J=6Hz), 2.64(1H,ddd,J=7,10,14Hz), 3.59(1H,dt,J=3,10Hz), 3.92(1H,d,J=7Hz), 4.17(1H,d,J=9Hz), 4.32(1H,dd,J=3,18Hz), 4.35(1H,d,J=9Hz), 4.41(1H,dd,J=5,18Hz), 4.60(1H,d,J=12Hz), 4.75(1H,d,J=12Hz), 4.79(1H,d,J=12), 4.91(1H,d,J=10Hz), 4.92(1H,d,J=12Hz), 4.99(1H,brd,J=10Hz), 5.22(1H,d,J=2Hz), 5.58(1H,dd,J=7,11Hz), 5.71(1H,d,J=7Hz), 6.13-6.20(1H,m), 6.26(1H,s), 7.51 (2H,t,J=8Hz), 7.63(1H,tt,J=2,8Hz), 8.10(2H,brdd,J=1,9Hz). (7)To a solution of 56 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-tert-butoxycarbonylamino-3-cyclopropyl-2-hydroxyacetoxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one in 3 ml of tetrahydrofuran are added 31 mg of (3S)-3-benzyloxycarbonylamino-3-carbamoylpropionic acid, 25 mg of 1,3-dicyclohexylcarbodiimide and about 1 mg of 4-dimethylaminopyridine. The reaction mixture is stirred at room temperature for 4 hours and condensed. The residue is dissolved in ethyl acetate and insoluble materials are removed by filtration. The filtrate is washed, dried and evaporated to remove the solvent. The residue is purified by thin layer chromatography to give 51 mg of 4α-acetoxy-2α-benzoyloxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2[(3S)-3-benzyloxycarbonylamino-3-carbamoylpropionyloxyacetoxy]-3-cyclopropylpropionyloxy}-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one. Yield:76% ESI-MS(m/z, ammonium acetate):1445(M+NH 4 + +2) IR(nujol,cm -1 ):3363,1757,1723 NMR(CDCl 3 , δ ):0.17-0.23(1H,m), 0.49-0.53(1H,m), 0.62-0.69(2H,m), 1.10-1.18(1H,m), 1.18(3H,s), 1.23(3H,s), 1.33(9H,s), 1.72(1H,s), 1.84(3H,s), 2.03(3H,s), 2.03-2.06(1H,m), 2.29-2.32(2H,m), 2.37(3H,s), 2.62(1H,ddd,J=7,10,14Hz), 2.72(1H,dd,J=5,17Hz), 3.31(1H,dd,J=4,17Hz), 3.53(1H,dt,J=3,9Hz), 3.90(1H,d,J=7Hz), 4.16(1H,d,J=8Hz), 4.34(1H,d,J=7Hz), 4.59(1H,d,J=12Hz), 4.68(1H,d,J=16Hz), 4.69-4.73(1H,m), 4.75(1H,d,J=12Hz), 4.78(1H,d,J=12Hz), 4.90(1H,d,J=12Hz), 4.92(1H,d,J=16Hz), 4.97(1H,brd,J=9Hz), 5.13(1H,br), 5.14(1H,d,J=12Hz), 5.16(1H,d,J=12Hz), 5.55(1H,dd,J=10,7Hz), 5.70(1H,d,J=10Hz), 6.02(1H,brs), 6.11-6.21(2H,m), 6.24(1H,s), 6.54(1H,brs), 6.60-6.63(1H,m), 7.35-7.38(5H,m), 7.50(2H,t,J=8Hz), 7.63(1H,tt,J=7,2Hz), 8.10(2H,brd,J=7Hz). (8)4α-Acetoxy-2α-benzoyloxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-[(3S)-3-benzyloxycarbonylamino-3-carbamoylpropionyloxyacetoxy]-3- cyclopropylpropionyloxy}-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one is treated in the same manner as described in Example 1(13) or Example 2 to give 4α-acetoxy-2α-benzoyloxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-[(3S)-3-benzyloxycarbonylamino-3-carbamoylpropionyloxyacetoxy]-3-cyclopropylpropionyloxy}-5β,20-epoxy-1β,7β,10β-trihydroxytax-11-en-9-one. FAB-MS(m/z):1078(M+H + ) IR(nujol,cm -1 ):3400,1700 NMR(CDCl 3 , δ ):0.12-0.24(1H,m), 0.45-0.57(1H,m), 0.59-0.72(2H,m), 1.05-1.21(1H,m), 1.13(3H,s), 1.16(3H,s), 1.33(9H,s), 1.62-1.98(1H,m), 1.67(1H,s), 1.71(3H,s), 1.89(3H,s), 2.14-2.38(2H,m), 2.37(3H,s), 2.47-2.62(1H,m), 2.66-2.76(1H,m), 3.28-3.40(1H,m), 3.45-3.59(1H,m), 3.89(1H,d,J=7Hz), 4.10-4.28(3H,m), 4.32(1H,d,J=9Hz), 4.66-4.69(2H,m), 4.86-4.98(1H,m), 4.95(1H,d,J=9Hz), 5.10(1H,brs), 5.15(2H,brs), 5.24(1H,brs), 5.68(1H,d,J=7Hz), 6.03-6.28(3H,m), 6.72-6.86(1H,m), 7.31-7.41(5H,m), 7.47-7.55(2H,m), 7.57-7.66(1H,m), 8.11(2H,d,J=8Hz). (9)4α-Acetoxy-2α-benzoyloxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-[(3S)-3-benzyloxycarbonylamino-3-carbamoylpropionyloxyacetoxy]-3-cyclopropylpropionyloxy}-5β,20-epoxy-1β,7β,10β-trihydroxytax-11-en-9-one is treated in the same manner as described in Example 1(14) to give 4α-acetoxy-2α-benzoyloxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-[(3S)-3-amino-3-carbomoylpropionyloxyacetoxy]-3-cyclopropylpropionyloxy}-5β,20-epoxy-1β,7β,10β-trihydroxytax-11-en-9-one methanesulfonate. FAB-MS(m/z):944(M+H + ) IR(nujol,cm -1 ):3400,1740,1700 NMR(DMSO-d 6 , δ ):0.09-0.19(1H,m), 0.31-0.41(1H,m), 0.47-0.59(2H,m), 0.95-1.10(1H,m), 1.02(3H,s), 1.03(3H,s), 1.35(9H,s), 1.54(3H,s), 1.62-1.72(1H,m), 1.79(3H,s), 2.17-2.34(3H,m), 2.30(3H,s), 2.32(3H,s), 2.95(1H,dd,J=8,17Hz), 3.08(1H,ddlike), 3.34-3.47(1H,m), 3.74(1H,d,J=7Hz), 4.02-4.14(4H,m), 4.67(1H,s), 4.89(2H,s), 4.95(1H,d,J=11Hz), 4.98(1H,d,J=2Hz), 5.05(1H,d,J=7Hz), 5.07(1H,d,J=4Hz), 5.14(1H,d,J=2Hz), 5.47(1H,d,J=7Hz), 5.95(1H,t,J=9Hz), 7.21(1H,d,J=9Hz), 7.56(2H,t,J=8Hz), 7.62-7.72(2H,m), 7.87(1H,brs), 8.02(2H,d,J=7Hz), 8.09(3H,brs). Example 5 (1)To a solution of 202 mg of [(3S)-3-benzyloxycarbonylamino-3-carbamoylpropionyloxy]acetic acid in 4 ml of tetrahydrofuran are added successively 90 ml of triethylamine and 75 ml of isopropyloxycarbonylchloride under argon atmosphere at -10°C. The reaction mixture is stirred for 15 minutes. To the mixture is added slowly a solution of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-tert-butoxycarbonylamino-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β,7β,10β -trihydroxytax-11-en-9-one obtained in Example 2 in 2 ml of tetrahydrofuran. The reaction mixture is stirred at -10-0°C for 7 hours. To the mixture is added saturated aqueous solution of sodium hydrogen carbonate, and the mixture is extracted with ethyl acetate. The extract is washed, dried and evaporated to remove the solvent. The residue is purified by silica gel column chromatography (solvent; hexane:ethyl acetate:ethanol=15:15:1) to give 73 mg of 4α-acetoxy-2α-benzoyloxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-[(3S)-3-benzyloxycarbonylamino-3-carbamoylpropionyloxyacetoxy]-3-cyclopropylpropionyloxy}-5β,20-epoxy-1β,7β,10β-trihydroxytax-11-en-9-one. The physical properties of the product are the same as those of the compound of Example 4(8). (2)4α-Acetoxy-2α-benzoyloxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-3-[(3S)-3-benzyloxycarbonylamino-3-carbamoylpropionyloxyacetoxy]-3-cyclopropylpropionyloxy}-5β,20-epoxy-1β,7β,10β-trihydroxytax-11-en-9-one is treated in the same manner as described in Example 1(14) to give 4α-acetoxy-2α-benzoyloxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-[(3S)-3-amino-3-carbamoylpropionyloxyacetoxy]-3-cyclopropylpropionyloxy}-5β,20-epoxy-1β,7β,10β-trihydroxytax-11-en-9-one methanesulfonate. The physical properties of the product are the same as those of the compound of Example 4(9). Example 6 (1)A solution of 2.07 g of ethyl (2R,3S)-3-cyclopropyl-3-tert-butoxycarbonylamino-2-hydroxypropionate and 213 mg of pyridinium p-toluenesulfonate in 125 ml of toluene is refluxed under heating. To the mixture is added dropwise a solution of 2.76 g of p-anisaldehydedimethylacetal in 25 ml of toluene for 20 minutes. The reaction mixture is evaporated to remove the generated methanol. The mixture is stirred under heating for 1.5 hours and cooled. After the reaction mixture is condensed under reduced pressure, ethyl acetate and water are added to the residue. The ethyl acetate layer is obtained by separation. The aqueous layer is extracted with ethyl acetate. The extract is washed with water and brine, dried and condensed under reduced pressure. The residue is purified by silica gel column chromatography (solvent; toluene:ethyl acetate=40:1) to give 1.572 g of ethyl (4S,5R)-3-tert-butoxycarbonyl-2-(4-methoxyphenyl)-4-cyclopropyl-5-oxazolidinecarboxylate (diastereomeric mixture). Yield:53% The physical properties of the main isomer only are shown. ESI-MS(m/z):392(M + H) IR(neat,cm -1 ):1750,1703 NMR(CDCl 3 , δ ):0.34-0.42(1H,m), 0.51-0.73(3H,m), 1.10-1 22(1H,m), 1.30(3H,t,J=7Hz), 1.58(9H,s), 3.63(1H,dd,J=2,9Hz), 3.82(3H,s), 4.24.(1H,q,J=7Hz), 4.25(1H,q,J=7Hz), 4.60(1H,d,J=2Hz), 6.32(1H,s), 6.90(2H,dt,J=2,9Hz), 7.45(2H,dt,J=2,9Hz). (2)To a solution of 881 mg of ethyl (4S,5R)-3-tert-butoxycarbonyl-2-(4-methoxyphenyl)-4-cyclopropyl-5-oxazolidinecarboxylate (diastereomeric mixture) in 16 ml of methanol is added dropwise a solution of 64.7 mg of lithium hydroxide in 8 ml of water under cooling, and the mixture is stirred at room temperature for 1 hour. After the reaction mixture is evaporated under reduced pressure to remove methanol, the residue is dissolved in chloroform. The pH of the solution is adjusted to pH 2 with 10 % hydrochloric acid. After extracted with chloroform, the extract is washed with brine twice, dried and evaporated to remove the solvent to give 792 mg of (4S,5R)-3-tertbutoxycarbonyl-2-(4-methoxyphenyl)-4-cyclopropyl-5-oxazolidinecarboxylic acid. Yield:97% The physical properties of the main isomer only are shown. ESI-MS(m/z):386(M+Na) IR(neat,cm -1 ):3200,1754,1702,1669 NMR(CDCl 3 , δ ):0.37-0.46(1H,m), 0.51-0.76(3H,m), 1.09-1.21(1H,m), 1.38(9H,s), 3.71(1H,dd,J=2,9Hz), 3.82(3H,s), 4.40(1H,broads), 4.64(1H,d,J=2Hz), 6.34(1H,s), 6.90(2H,dt,J=2,9Hz), 7.44(2H,dt,J=2,9Hz). (3)To a solution of 722 mg of (4S,5R)-3-tert-butoxycarbonyl-2-(4-methoxyphenyl)-4-cyclopropyl-5-oxazolidinecarboxylic acid in 23 ml of toluene are added 495 mg of dicyclohexylcarbodiimide, 93 mg of 4-(N,N-dimethylamino)pyridine and 1.345 g of 4α-acetoxy-2α-benzoyloxy-5β,20-epoxy-1β,13α-dihydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one at room temperature. The mixture is stirred at 80 °C for 2 hours. Insoluble materials are removed by filtration. The filtrate is condensed under reduced pressure. The residue is purified by silica gel column chromatography (solvent; hexane:ethyl acetate=3:1) to give 1.713 g (92%yield) of 4α-acetoxy-2α-benzoyloxy-13α-[(4S,5R)-3-tert-butoxycarbonyl-(2S)-(4-methoxyphenyl)-4-cyclopropyloxazolidin-5-ylcarbonyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one and 4α-acetoxy-2α-benzoyloxy-13α-[(4S,5R)-3-tert-butoxycarbonyl-(2R)-(4-methoxyphenyl)-4-cyclopropyloxazolidin-5-ylcarbonyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one. m.p.:158.8-165.1°C ESI-MS(m/z):1258(M+NH 4 ) IR(nujol,cm -1 ):3488,1761,1729,1704 NMR(CDCl 3 , δ ):0.38-0.46(1H,m), 0.54-0.90(4H,m), 1.21(3H,s), 1.29(3H,s), 1.37(9H,s), 1.72(1H,s), 1.87(3H,s), 2.03-2.13(1H,m), 2.09(3H,d,J=1Hz), 2.24-2.38(2H,m), 2.33(3H,s), 2.63-2.72(1H,m), 3.78(1H,dd,J=2,9Hz), 3.85(3H,s), 3.96(1H,d,J=7Hz), 4.18(1H,d,J=9Hz), 4.34(1H,d,J=9Hz), 4.61(1H,d,J=12Hz), 4.73(1H,d,J=2Hz), 4.78(2H,s), 4.91(1H,d,J=12Hz), 4.97-5.02(1H,m), 5.61(1H,dd,J=7,11Hz), 5.71(1H,d,J=7Hz), 6.25-6.32(1H,m), 6.28(1H,s), 6.37(1H,s), 6.95(2H,dt,J=2,9Hz), 7.48(2H,m), 7.53(2H,dt,J=2,9Hz), 7.62(1H,tt,J=1,7Hz), 8.07(2H,dd,J=1,7Hz). m.p.:176.1-184.3°C ESI-MS(m/z):1258(M+NH 4 ) IR(nujol,cm -1 ):3325,1761,1728,1708 NMR(CDCl 3 , δ ):0.28-0.37(1H,m), 0.51-0.60(1H,m), 0.76-0.92(3H,m), 1.16(3H,s), 1.23(3H,s), 1.24(9H,s), 1.52(3H,s), 1.67(1H,s), 1.82(3H,s), 2.11-2.23(1H,m), 2.27-2.36(2H,m), 2.28(3H,s), 2.55-2.64(1H,m), 3.79(3H,s), 3.84(1H,dd,J=3,11Hz), 4.11(1H,d,J=8Hz), 4.13(1H,d,J=7Hz), 4.32(1H,d,J=8Hz), 4.50(1H,d,J=3Hz), 4.59(1H,d,J=12Hz), 4.75(1H,d,J=12Hz), 4.80(1H,d,J=12Hz), 4.89(1H,d,J=12Hz), 4.91-4.96(1H,m), 5.10(1H,dd,J=7,11Hz), 5.66(1H,d,J=7Hz), 5.97(1H,m), 6.10(1H,s), 6.12(1H,s), 6.87(2H,dt,J=2,9Hz), 7.26(2H,dt,J=2,9Hz), 7.49(2H,m), 7.63(1H,tt,J=1,7Hz), 8.06(2H,dt,J=1,7Hz). (4)To a solution of 52.9 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(4S,5R)-3-tert-butoxycarbonyl-2-(4-methoxyphenyl)-4-cyclopropyloxazolidin-5-ylcarbonyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one in 2.1 ml of methanol is added 8.6 mg of p-toluenesulfonic acid monohydrate at room temperature. The mixture is stirred at room temperature for 23 hours. After the reaction mixture is evaporated under reduced pressure to remove methanol, ethyl acetate, and saturated aqueous solution of sodium hydrogen carbonate is added to the residue. The mixture is stirred. The resulting ethyl acetate layer is washed with water and brine, dried, condensed under reduced pressure and purified by preparative thin layer chromatography (solvent; hexane:ethyl acetate=2:1) to give 30.7 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-tert-butoxycarbonylamino-3-cyclopropyl-2- hydroxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one. The physical properties of the product are the same as those of the compound of Example 1(11). Yield:64% (5)4α-Acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-tert-butoxycarbonylamino-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one and [(3S)-3-benzyloxycarbonylamino-3-ethoxycarbonylpropionyloxy]acetic acid are treated in the same manner as described in Example 1(12)-(14) to give 4α-acetoxy-2α-benzoyloxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-[(3S)-3-amino-3-ethoxycarbonylpropionyloxyacetoxy]-3-cyclopropylpropionyloxy}-5β,20-epoxy-1β,7β,10β-trihydroxytax-11-en-9-one methanesulfonate. The physical properties of the product are the same as those of the compound of Example 1(14). Example 7 (1)Ethyl (4S,5R)-3-tert-butoxycarbonyl-2-(4-methoxyphenyl)-4-cyclopropyl-5-oxazolidinecarboxylate (diastereomeric mixture) obtained in Example 6(1) is purified by column chromatography to give ethyl (4S,5R)-3-tert-butoxycarbonyl-2-(4-methoxyphenyl)-4-cyclopropyl-5-oxazolidinecarboxylate. A 87 mg of lithium hydroxide is added under ice-cooling to a solution of 1.03 g of ethyl (4S,5R)-3-tert-butoxycarbonyl-2-(4-methoxyphenyl)-4-cyclopropyl-5-oxazolidinecarboxylate in a mixture of 20 ml of methanol and 10 ml of water. The mixture is stirred at room temperature for 30 minutes. The reaction mixture is evaporated under reduced pressure to remove methanol. The pH of the solution of the residue in ethyl acetate is adjusted to pH 2 with 1N hydrochloric acid under ice-cooling. After the mixture is extracted with ethyl acetate, the extract is washed with brine, dried and evaporated to remove the solvent to give 1.20 g of (4S,5R)-3-tert-butoxycarbonyl-2-(4-methoxyphenyl)-4-cyclopropyl-5-oxazolidinecarboxylic acid quantitatively. ESI-MS(m/z):386(M + +Na) IR(neat,cm -1 ):3080,1755,1702 NMR(CDCl 3 , δ ):0.37-0.46(1H,m), 0.52-0.77(3H,m), 1.11-1.23(1H,m), 1.38(9H,s), 3.71(1H,brd), 3.82(3H,s), 4.65(1H,d,J=2Hz), 6.34(1H,s), 6.88-6.93(2H,m), 7.42-7.47(2H,m). (2)To a solution of 980 mg of (4S,5R)-3-tert-butoxycarbonyl-2-(4-methoxyphenyl)-4-cyclopropyl-5-oxazolidinecarboxylic acid and 1.15 g of 4α-acetoxy-2α-benzoyloxy-5β,20-epoxy-1β,13α-dihydroxy-7β-triethylsilyloxy-10β-(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one in 60 ml of toluene are added 594 mg of dicyclohexylcarbodiimide and 110 mg of dimethylaminopyridine. The mixture is stirred at 60 °C for 1 hour. Insoluble materials are removed by filtration. The filtrate is evaporated under reduced pressure to remove the solvent. To the residue is added ethyl acetate and 1% hydrochloric acid, and the mixture is extracted with ethyl acetate twice. The extract is washed with saturated aqueous solution of sodium hydrogen carbonate and brine, dried and evaporated to remove the solvent. The residue is purified by silica gel column chromatography (solvent; hexane:ethyl acetate=2:1) to give 1.68 g of 4α-acetoxy-2α-benzoyloxy-13α-[(4S,5R)-3-tert-butoxycarbonyl-2-(4-methoxyphenyl)-4-cyclopropyloxazolidin-5-ylcarbonyloxy]-5β,20-epoxy-1β-hydroxy-7β-triethylsilyloxy-10β-(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one quantitatively. m.p.:>130°C(slowly decomposed) ESI-MS(m/z):1196(M + +NH 4 ) IR(nujol,cm -1 ):1730,1460,1380,1245 NMR(CDCl 3 , δ ):0.36-0.46(1H,m), 0.53-0.86(3H,m), 0.60(6H,brq), 0.94(9H,t,J=7Hz), 1.20-1.30(1H,m), 1.24(3H,s), 1.26(3H,s), 1.36(9H,s), 1.72(4H,s), 1.86-1.97(1H,m), 2.11(3H,d,J=1Hz), 2.23-2.36(2H,m), 2.31(3H,s), 2.51-2.64(1H,m), 3.76(1H,dd,J=2,9Hz), 3.82(1H,d,J=7Hz), 3.84(3H,s), 4.17(1H,d,J=8Hz), 4.31(1H,d,J=8Hz), 4.50(1H,dd,J=7,10Hz), 4.73(1H,d,J=2Hz), 4.80(2H,s), 4.96(1H,d,J=8Hz), 5.70(1H,d,J=7Hz), 6.26(1H,brt), 6.30(1H,s), 6.38(1H,s), 6.92-6.98(2H,m), 7.44-7.56(4H,m), 7.57-7.64(1H,m), 8.03-8.10(2H,m). (3)To a solution of 40 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(4S,5R)-3-tert-butoxycarbonyl-2-(4-methoxyphenyl)-4-cyclopropyloxazolidin-5-ylcarbonyloxy]-5β,20- epoxy-1β-hydroxy-7β-triethylsilyloxy-10β-(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one in 1 ml of methanol is added 14 mg of p-toluenesulfonic acid monohydrate at room temperature. The mixture is stirred at room temperature for 2 hours. Then, 14 mg of p-toluenesulfonic acid monohydrate is added thereto. The mixture is stirred at room temperature for 4 hours. After the reaction mixture is condensed, the residue is extracted with ethyl acetate by adding ethyl acetate and saturated aqueous solution of sodium hydrogen carbonate thereto. The extract is washed with brine, dried and evaporated to remove the solvent. The residue is purified by thin layer chromatography (solvent; hexane:ethyl acetate=3:2) to give 22 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-tert-butoxycarbonylamino-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β,7β-dihydroxy-10β-(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one. Yield:69% m.p.:>155°C(slowly decomposed) ESI-MS(m/z):965(M + +NH 4 ),963,948(M + +H) IR(neat,cm -1 ):3520,1720,1250 NMR(CDCl 3 , δ ):0.22-0.31(1H,m), 0.44-0.53(1H,m), 0.60-0.69(2H,m), 1.20-1.28(1H,m), 1.18(3H,s), 1.28(3H,s), 1.32(9H,s), 1.70(4H,s), 1.83-1.95(1H,m), 1.95(3H,d,J=1Hz), 2.23(1H,d,J=5Hz), 2.30-2.35(2H,m), 2.37(3H,s), 2.50-2.64(1H,m), 3.25-3.33(1H,m), 3.33(1H,d,J=6Hz), 3.77(1H,d,J=7Hz), 4.18(1H,d,J=8Hz), 4.33(1H,d,J=9Hz), 4.35-4.41(2H,m), 4.77(1H,d,J=12Hz), 4.88(1H,brd), 4.89(1H,d,J=12Hz), 4.97(1H,brd), 5.70(1H,d,J=7Hz), 6.17(1H,s), 6.18(1H,brt), 7.47-7.54(2H,m), 7.59-7.65(1H,m), 8.08-8.13(2H,m). (4)To a solution of 20 mg of 4α-acetoxy-2α-benzoyloxy-13α-[(2R,3S)-3-tert-butoxycarbonylamino-3-cyclopropyl-2-hydroxypropionyloxy]-5β,20-epoxy-1β,7β-dihydroxy-10β-(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one and 7.5 mg of [(3S)-3-benzyloxycarbonylamino-3-carbamoylpropionyloxy]acetic acid in 1.5 ml of dichloromethane are added 5.0 mg of dicyclohexylcarbodiimide and 1.3 mg of dimethylaminopyridine under ice-cooling. The mixture is stirred under ice-cooling for 20 minutes and at room temperature for 4 hours. Insoluble materials are removed by filtration. After the filtrate is condensed under reduced pressure, the residue is extracted with ethyl acetate by adding ethyl acetate and 1% aqueous hydrochloric acid thereto. The extract is washed with saturated aqueous solution of sodium hydrogen carbonate and brine, dried and evaporated to remove the solvent. The residue is purified by thin layer chromatography (solvent; hexane:ethyl acetate=1:4) to give 13 mg of 4α-acetoxy-2α-benzoyloxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-[(3S)-3-benzyloxycarbonylamino-3-carbamoylpropionyloxyacetoxy]-3-cyclopropylpropionyloxy}-5β,20-epoxy-1β,7β-dihydroxy-10β-(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one. Yield:49% m.p.:>140°C(slowly decomposed) ESI-MS(m/z):1269(M + +NH 4 ) IR(neat,cm -1 ):3360,1700-1750,1505 NMR(CDCl 3 , δ ):0.15-0.23(1H,m), 0.47-0.56(1H,m), 0.60-0.70(2H,m), 1.15-1.20(1H,m), 1.16(3H,s), 1.24(3H,s), 1.30(9H,s), 1.69(4H,s), 1.83-1.99(1H,m), 1.96(3H,brs), 2.25-2.35(3H,m), 2.37(3H,s), 2.51-2.63(1H,m), 2.70(1H,dd,J=4,17Hz), 3.31(1H,dd,J=4,17Hz), 3.55(1H,brt), 3.77(1H,d,J=7Hz), 4.17(1H,d,J=8Hz), 4.32(1H,d,J=9Hz), 4.33-4.43(1H,m), 4.66-4.74(1H,m), 4.67(1H,d,J=16Hz), 4.76(1H,d,J=12Hz), 4.89(1H,d,J=12Hz), 4.93(1H,d,J=16Hz), 4.98(1H,brd), 5.10(1H,d,J=3Hz), 5.15(2H,s), 5.69(1H,d,J=7Hz), 6.00(1H,br), 6.13-6.21(2H,m), 6.17(1H,s), 6.50(1H,br), 6.74(1H,brd), 7.33-7.39(5H,m), 7.47-7.53(2H,m), 7.58-7.65(1H,m), 8.09-8.14(2H,m). (5)To a solution of 35 mg of 4α-acetoxy-2α-benzoyloxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-[(3S)-3-benzyloxycarbonylamino-3-carbamoylpropionyloxyacetoxy]-3-cyclopropylpropionyloxy}-5β,20-epoxy-1β,7β-dihydroxy-10β-(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one in 2.0 ml of methanol are added 55 mg of zinc and 0.4 ml of acetic acid at room temperature. The mixture is stirred at 40 °C for 2 hours. The solid materials are removed by filtration. After the filtrate is condensed under reduced pressure, the residue is extracted with ethyl acetate by adding ethyl acetate and 1% hydrochloric acid to the residue under ice-cooling. The extract is washed with the saturated aqueous solution of sodium hydrogen carbonate and brine, dried and evaporated to remove the solvent. The residue is purified by thin layer chromatography (solvent; chloroform:methanol=10:1) to give 24 mg of 4α-acetoxy-2α-benzoyloxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-[(3S)-3-benzyloxycarbonylamino-3-carbamoylpropionyloxyacetoxy]-3-cyclopropylpropionyloxy}-5β,20-epoxy-1β,7β,10β-trihydroxytax-11-en-9-one. The physical properties of the product are the same as those of the compound of Example 4(8). Yield:80% (6)4α-acetoxy-2α-benzoyloxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-[(3S)-3-benzyloxycarbonylamino-3-carbamoylpropionyloxyacetoxy]-3-cyclopropylpropionyloxy}-5β,20-epoxy-1β,7β,10β-trihydroxytax-11-en-9-one is treated in the same manner as described in Example 1(14) to give 4α-acetoxy-2α-benzoyloxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-[(3S)-3-amino-3-carbamoylpropionyloxyacetoxy]-3-cyclopropylpropionyloxy}-5β,20-epoxy-1β,7β,10β-trihydroxytax-11-en-9-one methanesulfonate. The physical properties of the product are the same as those of the compound of Example 4(9). Example 8-12 The corresponding starting compounds are treated in the same manner as described in Example 1 or 4-7 to give the compounds shown in Tables 8-11. Example 13-14 The corresponding starting compounds are treated in the same manner as described in Example 1(1)-(11) and 2 to give the compounds shown in Tables 12. Example 15-20 The corresponding starting compounds are treated in the same manner as described in Example 1 or 4-7 to give the compounds shown in Tables 13-18. Example 21-24 The corresponding starting compounds are treated in the same manner as described in Example 1 or 4-7 to give the compounds shown in Tables 19. Example 25 (1)To 13.13 g of (1R,2R)-2-methylcyclopropyl-1,2-bis(isopropyloxycarbonyl)methylene acetal in a mixture of 40 ml of tetrahydrofuran and 80 ml of water is added 9.15 g of p-toluenesulfonic acid monohydrate. The reaction mixture is refluxed under heating for 8 hours. After the reaction mixture is cooled, a saturated aqueous solution of sodium hydrogen carbonate and 400 ml of toluene are added to the mixture. The aqueous layer is extracted with toluene twice. After the organic layer is dried over sodium sulfate, inorganic materials are removed by filtration. A 27.09 g of benzyloxycarbonylmethylenetriphenylphosphorane is added to the solution. The mixture is stirred at 80 °C for 18 hours. The solvent is removed in vacuo and the residue is purified by silica gel column chromatography (solvent;hexane:ethyl acetate=15:1) to give 6.67 g of benzyl trans-3-(2-methyl)cyclopropylacrylate. Benzyl trans-3-(2-methyl)cyclopropylacrylate is treated in the same manner as described in Example 1(2)-(8) to give (4S,5R)-3-tert-butoxycarbonyl-2,2-dimethyl-4-[(1R,2R)-2-methyl]cyclopropyl-5-oxazolidinecarboxylic acid. m.p.:86-91°C FAB-MS(m/z):300(MH + ) (2)(4S,5R)-3-tert-Butoxycarbonyl-2,2-dimethyl-4-[(1R,2R)-2-methyl]cyclopropyl-5-oxazolidinecarboxylic acid and 4α-acetoxy-2α-benzoyloxy-5β,20-epoxy-1β,13α-dihydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one are treated in the same manner as described in Example 1(9) to give 4α-acetoxy-2α-benzoyloxy-13α-{(4S,5R)-3-tert-butoxycarbonyl-2,2-dimethyl-4-[(1R,2R)-2-methyl]cyclohexyloxazolidin-5-ylcarbonyloxy}-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one. FAB-MS(m/z):1198(M + +Na) (3)4α-Acetoxy-2α-benzoyloxy-13α-{(4S,5R)-3-tert-butoxycarbonyl-2,2-dimethyl-4-[(1R,2R)-2-methyl]cyclohexyloxazolidin-5-ylcarbonyloxy}-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichlorethoxycarbonyloxy)tax-11-en-9-one is treated in the same manner as described in Example 2 to give 4α-acetoxy-2α-benzoyloxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-hydroxy-3-[1R,2R)-2-methyl]cyclopropylpropionyloxy}-5β,20-epoxy-1β,7β,10β-trihydroxytax-11-en-9-one. m.p.:167-174°C FAB-MS(m/z).:808(M + +Na) (4)4α-Acetoxy-2α-benzoyloxy-13α-{(2R,3S)-3-tertbutoxycarbonylamino-2-hydroxy-3-[(1R,2R)-2-methyl]cyclopropylpropionyloxy}-5β,20-epoxy-1β,7β,10β-trihydroxytax-11-en-9-one is treated in the same manner as described in Example 5 to give 4α-acetoxy-2α-benzoyloxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-[(3S)-3-amino-3-ethoxycarbonylpropionyloxyacetoxy]-3-[(1R,2R)-2-methyl]cyclopropylpropionyloxy}-5β,20-epoxy-1β,7β,10β-trihydroxytax-11-en-9-one methanesulfonate. m.p.:>152°C(decomposed) FAB-MS(m/z):1009(M + +Na) IR(nujol,cm -1 ):3400,1750,1720 NMR(300MHz,DMSO-d 6 , δ ):0.24-0.33(1H,m), 0.50-0.65(2H,m), 0.70-0.81(1H,m), 0.99(3H,d,J=6Hz), 1.03(6H,s), 1.24(3H,t,J=7Hz), 1.33(9H,s), 1.54(3H,s), 1.59-1.74(1H,m), 1.78(3H,s), 2.19-2.27(3H,m), 2.31(6H,s), 3.08(1H,dd,J=6,18Hz), 3.25-3.40(1H,m), 3.43-3.54(1H,m), 3.74(1H,d,J=7Hz), 4.01-4.13(3H,m), 4.16-4.28(2H,m), 4.40(1H,t,J=6Hz), 4.64(1H,s), 4.90(2H,s), 4.92-4.99(2H,m), 5.05(1H,d,J=8Hz), 5.11(1H,d,J=4Hz), 5.14(1H,s), 5.47(1H,d,J=7Hz), 5.89-6.00(1H,m), 7.15(1H,d,J=9Hz), 7.51-7.59(2H,m), 7.64-7.72(1H,m), 8.02(2H,d-like,J=7Hz), 8.37(3H,brs). Example 26 4α-Acetoxy-2α-benzoyloxy-13α-{(4S,5R)-3-tert-butoxycarbonyl-2,2-dimethyl-4-[(1R,2R)-2-methyl]cyclohexyloxazolidin-5-ylcarbonyloxy}-5β,20-epoxy-1β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one obtained in Example 25(2) is treated in the same manner as described in Example 1(10)-(14) to give 4α-acetoxy-2α-benzoyloxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-[(3S)-3-amino-3-ethoxycarbonylpropionyloxyacetoxy]-3-[(1R,2R)-2-methyl]cyclopropylpropionyloxy}-5β,20-epoxy-1β,7β,10β-trihydroxytax-11-en-9-one methanesulfonate. The physical properties of the product are the same as those of the compound of Example 25(4). Reference Example A solution of 3.29 g of 4α-acetoxy-2α-benzoyloxy-5β,20-epoxy-1β,10β,13α-trihydroxy-7β-triethylsilyloxytax-11-en-9-one in 10 ml of pyridine is cooled in an ice-bath, and 1.38 ml of trichloroethylformic acid chloride is added dropwise thereto. The mixture is warmed to room temperature and stirred for 7 hours. The reaction mixture is extracted with ethyl acetate by pouring into a mixture of ethyl acetate and ice- water. The extract is washed with water and brine, dried over magnesium sulfate and evaporated to remove the solvent. The residue is purified by silica gel column chromatography (solvent; toluene:ethyl acetate=4:1) to give 4α-acetoxy-2α-benzoyloxy-5β,20-epoxy-1β-hydroxy-7β-triethylsilyloxy-10β-(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one. Yield:74% FAB-MS(m/z):835(MH + ) IR(nujol,cm -1 ):3470,1770,1725,1710 NMR(CDCl 3 , δ ):0.58(6H,q,J=7Hz), 0.93(9H,t,J=7Hz), 1.64(3H,s), 1.85-1.92(1H,m), 2.08(1H,d,J=5Hz), 2.20(3H,s), 2.29(3H,s), 2.20-2.30(2H,m), 2.50-2.58(1H,m), 3.84(1H,d,J=7Hz), 4.15(1H,d,J=8Hz), 4.31(1H,d,J=8Hz), 4.47-4.51(1H,m), 4.79(1H,d,J=12Hz), 4.83(1H,d,J=12Hz), 4.83-4.88(1H,m), 4.96(1H,d,J=8Hz), 5.64(1H,d,J=7Hz), 6.30(1H,s), 7.26-7.63(3H,m), 8.10(2H,d,J=7Hz). Effects of the Invention The compound [I] or a pharmaceutically acceptable salt thereof of the present invention has high water-solubility, high stability, and also excellent antitumor activity. For example, the taxol derivative of the present invention exhibits excellent antitumor activities and life-prolonging effects on mice to which P-388 cells are transplanted intraperitoneally, nude mice to which human breast carcinoma MX-1 cells are transplanted subcutaneously, and mice to which B16 melanoma cells are transplanted intraperitoneally or subcutaneously. Further, the taxol derivative or a pharmaceutically acceptable salt thereof of the present invention has low toxicity. For example, when 4α-acetoxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-[((3S)-3-amino-3-ethoxycarbonyl propionyloxy)acetoxy]-3-cyclopropylpropionyloxy}-2α-benzoyloxy-5β,20-epoxy-1β,7β,10β-trihydroxytax-11-en-9-one methanesulfonate is intravenously administered (25 mg/kg) for 5 days once a day to BDF 1 mice to which B16 melanoma cells have been transplanted subcutaneously, no mice deaths are observed in more than 30 days. Thus, the compound [I] of the present invention can suitably be used for medical treatment of a wide range of tumors such as breast cancer, ovary cancer, lung cancer and malignant melanoma.

Claims: A compound represented by the formula [I]: wherein R 3 represents a C 2-7 alkanoyl group; R 4 represents a benzoyl group which may be substituted with a group selected from a C 1-6 alkyl group, a C 1-6 alkoxy group and a halogen atom; ring A is a cyclopropane ring which may be substituted with 1 or 2 groups selected from a halogen atom, a C 1-6 alkyl group, and a C 1-6 alkoxy group; X represents a single bond or a group represented by -O-,-S- or -NH-; R is a C 1-6 alkyl group which may be substituted with 1 to 3 groups selected from a halogen atom and a C 1-6 alkoxy group, wherein said C 1-6 alkyl group may have attached a 3- to 5-membered cycloalkyl moiety, a phenyl group which may be substituted with 1 or 2 C 1-6 alkoxy groups, a furyl group, or a thienyl group; E represents a hydrogen atom or a group represented by -CO(CH 2 ) n ZY; Y represents a residue obtained from asparagine, aspartic acid, glutamine, glutamic acid, proline, glycine, alanine, β-alanine, or a dipeptide consisting of these amino acids by removing the hydroxyl group from one carboxyl group, wherein the amino group existing in said residue may be protected with a benzyloxycarbonyl group, and the existing carboxyl group in said resident may be esterified with a C 1-6 alkyl group which may be substituted with a C 1-6 alkoxy group, or amidated; Z represents a group represented by the formula -O- or -NH-; and n represents 1,2,3,4,5 or 6, or a pharmaceutically acceptable salt thereof. The compound of claim 1, wherein E is a group represented by -CO(CH 2 ) n ZY. The compound of Claim 1 or 2, wherein ring A is a cyclopropane ring which may be substituted with a C 1-6 alkyl group; R is a C 1-6 alkyl group, furyl group or thienyl group; and Y is a residue obtained from asparagine, aspartic acid, glutamine, glutamic acid, proline, glycine, or β-alanine by removing the hydroxyl group from one carboxyl group, wherein the existing carboxyl group in said residue may be esterified with a C 1-6 alkyl group, or amidated. The compound of Claim 3, wherein R 3 is an acetyl group; R 4 is a benzoyl group; X is a group represented by -O-; R is a C 1-6 alkyl group; and Y is an asparaginyl group, aspartyl group, β-alanyl group, or prolyl group, wherein the carboxyl group may be esterified with a C 1-6 alkyl group, or amidated. A process for preparing a compound as claimed in claim 1 which comprises: (1) reacting a compound represented by the formula [II]: wherein R 1 represents a hydroxyl protecting group; R 2 represents a hydroxyl protecting group; R 3 , R 4 , and ring A are the same as defined above, or a salt thereof, with a compound represented by the formula [III]: RX-COOH wherein R and X are the same as defined above, a salt thereof, or a reactive derivative thereof to obtain the compound represented by a formula [V]: wherein R 1 , R 2 , R 3 , R 4 , ring A, X, and R are the same as defined above, and removing the protecting groups of the hydroxyl groups at the 7-position and the 10-position in this compound; (2) reacting the compound [II] or a salt thereof with the compound [III], a salt thereof, or a reactive derivative thereof, to obtain the compound [V], reacting the compound [V] with a compound represented by the formula [IV]: E'OH wherein E' is a group represented by -CO(CH 2 ) n ZY; Y, Z, and n are the same as defined above, a salt thereof, or a reactive derivative thereof, and removing the protecting groups of the hydroxyl groups at the 7-position and the 10-position in the compound obtained; or (3) reacting the compound [II] or a salt thereof with the compound [III], a salt thereof, or a reactive derivative thereof, to obtain the compound [V], removing the protecting groups of the hydroxyl groups at the 7-position and the 10-position in the compound [V], and then reacting the resulting compound with the compound of the formula [IV], a salt thereof, or a reactive derivative thereof, and then, if required, converting the resulting compound into a pharmaceutically acceptable salt thereof. A process for preparing a compound as claimed in claim 1 represented by the formula [I-a]: wherein E' represents a group represented by -CO(CH 2 ) n ZY; Y represents a residue obtained from asparagine, aspartic acid, glutamine, glutamic acid, proline, glycine, alanine, β-alanine, or a dipeptide consisting of these amino acids by removing the hydroxyl group from one carboxyl group, wherein the amino group existing in said residue may be protected with a benzyloxycarbonyl group, and the existing carboxyl group in said resident may be esterified with a C 1-6 alkyl group which may be substituted with a C 1-6 alkoxy group, or amidated; Z represents a group represented by the formula -O- or -NH-; and n represents 1, 2, 3, 4, 5 or 6, or a pharmaceutically acceptable salt thereof, which comprises reacting a compound represented by the formula [V]: wherein R 1 , R 2 , R 3 , R 4 , ring A, X, and R are the same as defined above, with a compound represented by the formula [IV]: E'OH wherein E' represents a group represented by -CO(CH 2 ) n ZY; Y, Z, and n are the same as defined above, removing hydroxyl protecting groups, if necessary, removing amino protecting groups and carboxyl group ester residues and then, if required, converting the resulting compound into a pharmaceutically acceptable salt thereof. A process for preparing a compound as claimed in claim 1 represented by the formula [I-a]: as defined in claim 6 which comprises reacting a compound represented by the formula [VII]: wherein R 1 , R 2 , R 3 , R 4 , ring A, X, R, Z, and n are the same as defined above, with a compound represented by the formula [VIII] YOH wherein Y is the same as defined above, removing the hydroxyl protecting groups, if necessary, removing amino protecting groups and carboxyl group ester residues, and then, if required, converting the resulting compound into a pharmaceutically acceptable salt thereof. A process for preparing a compound as claimed in claim 1 represented by the formula [I-b]: wherein R 3 represents a C 2-7 alkanoyl group; R 4 represents a benzoyl group which may be substituted with a group selected from a C 1-6 alkyl group, a C 1-6 alkoxy group and a halogen atom; ring A is a cyclopropane ring which may be substituted with 1 or 2 groups selected from a halogen atom, a C 1-6 alkyl group, and a C 1-6 alkoxy group, X represents a single bond or a group represented by -O-, -S- or -NH-; R is a C 1-6 alkyl group which may be substituted with 1 to 3 groups selected from a halogen atom and a C 1-6 alkoxy group, wherein said C 1-6 alkyl group may have attached a 3- to 5-membered cycloalkyl moiety, a phenyl group which may be substituted with 1 or 2 C 1-6 alkoxy groups, a furyl group, or a thienyl group; or a pharmaceutically acceptable salt thereof, which comprises reacting a compound represented by the formula [IX]: wherein R 6 represents a substituted phenyl group, ring A, X, and R are the same as defined above, or a reactive derivative thereof, with a compound represented by the formula [X]: wherein R 1 , R 2 , R 3 , and R 4 are the same as defined above, and then subjecting the resulting condensate to a cleavage reaction of the oxazolidine ring to obtain a compound represented by the formula [V]: wherein R 1 , R 2 , R 3 , R 4 , ring A, X, and R are the same as defined above, removing the protecting groups of the hydroxyl groups at the 7-position and the 10-position in the compound [V], and if required, converting the resulting compound into a pharmaceutically acceptable salt thereof. A process for preparing a compound represented by the formula [II]: wherein R 1 represents a hydroxyl protecting group; R 2 represents hydroxyl protecting group; R 3 represents a C 2-7 alkanoyl group; R 4 represents a benzoyl group which may be substituted with a group selected from a C 1-6 alkyl group, a C 1-6 alkoxy group and a halogen atom; ring A is a cyclopropane ring which may be substituted with 1 or 2 groups selected from a halogen atom, a C 1-6 alkyl group, and a C 1-6 alkoxy group; which comprises condensing a compound represented by the formula [XI]: wherein R 7 and R 8 represent C 1-6 alkyl groups, R 9 represents a protecting group, ring A is the same as defined above, or a reactive derivative thereof, with a compound represented by the formula [X]: wherein R 1 , R 2 , R 3 , and R 4 are the same as defined above, then subjecting the resulting condensate to steps of cleaving the oxazolidine ring and removing the protecting group R 9 , and if required, converting the resulting compound into a salt thereof. A process for preparing a compound represented by the formula [II]: as defined in claim 9 which comprises reducing a compound represented by the formula [XIII]: wherein R 1 , R 2 , R 3 , and R 4 are the same as defined above, and if required, converting the resulting compound into a salt thereof. A process for preparing a compound represented by the formula [II]: as defined in claim 9, which comprises subjecting a compound represented by the formula [XII]: wherein R 1 , R 2 , R 3 , R 4 , and ring A are the same as defined above, to an azide group introduction reaction using metal azide to obtain a compound represented by the formula [XIII]: wherein R 1 , R 2 , R 3 , R 4 , and ring A are the same as defined above, reducing the azide group of the compound [XIII], and if required, converting the resulting compound into a salt thereof. A compound represented by the formula [XIII]: wherein R 1 represents a hydroxyl protecting group: R 2 represents a hydroxyl protecting group; R 3 represents a C 2-7 alkanoyl group; R 4 represents a benzoyl group which may be substituted with a group selected from a C 1-6 alkyl group, a C 1-6 alkoxy group and a halogen atom; and ring A is a cyclopropane ring which may be substituted with 1 or 2 groups selected from a halogen atom, a C 1-6 alkyl group, and a C 1-6 alkoxy group. A compound represented by the formula [XII]: wherein R 1 represents a hydroxyl protecting group; R 2 represents a hydroxyl protecting group; R 3 represents a C 2-7 alkanoyl group: R 4 represents a benzoyl group which may be substituted with a group selected from a C 1-6 alkyl group, a C 1-6 alkoxy group and a halogen atom; and ring A is a cyclopropane ring which may be substituted with 1 or 2 groups selected from a halogen atom, a C 1-6 alkyl group, and a C 1-6 alkoxy group. A compound represented by the formula [IX]: wherein ring A is a cyclopropane ring which may be substituted with 1 or 2 groups selected from a halogen atom, a C 1-6 alkyl group, and a C 1-6 alkoxy group; R 6 represents a substituted phenyl group; X represents a single bond or a group represented by -O-, -S- or -NH-; and R is a C 1-6 alkyl group which may be substituted with 1 to 3 groups selected from a halogen atom and a C 1-6 alkoxy group, where said C 1-6 alkyl group may have attached a 3- to 5-membered cycloalkyl moiety; a phenyl group which may be substituted with 1 or 2 C 1-6 alkoxy groups, a furyl group, or a thienyl group. A compound represented by the formula [XI]: wherein ring A is a cyclopropane ring which may be substituted with 1 or 2 groups selected from a halogen atom, a C 1-6 alkyl group, and a C 1-6 alkoxy group R 7 and R 8 represent C 1-6 alkyl groups; and R 9 represents a protecting group or a reactive derivative thereof. A pharmaceutical composition which comprises a therapeutically effective amount of a compound of the formula [I] as set forth in any one of claims 1-3 in admixture with a conventional pharmaceutically acceptable carrier or diluent. The use of a compound of the formula [I] as set forth in any one of claims 1-3 in the manufacture of a medicament for the prophylaxis or treatment of a tumor. A compound of Claim 1 which is 4α-acetoxy-2α-benzoyl-oxy-13α-{(2R,3S)-3-tert-butoxycarbonylamino-2-[(3S)-3-amino-3-carbamoylpropionyloxy- acetoxy]-3-cyclopropylpropionyloxy}-5β,20-epoxy-1β,7β,10β-trihydroxytax-11-en-9-one or a pharmaceutically acceptable salt thereof.

Inventors: HASHIYAMA TOMIKI, NAKANISHI NORIYUKI, OHASHI MOTOAKI, TSUJIHARI KENJI, HASHIYAMA, TOMIKI, NAKANISHI, NORIYUKI, OHASHI, MOTOAKI, TSUJIHARI, KENJI
Applicants: TANABE SEIYAKU CO, TANABE SEIYAKU CO., LTD.
Application year: 1995
Main classification: C07D409
IPC codes: C07D413, C07D305, C07D407, C07D405, C07D409, C07D263