Patent ID: RE41366

Claim:
A method of synthesizing compounds of formula (1) in which either R 1 represents a hydrogen atom and R 2 represents a hydroxyl group, or R 1 and R 2 together form═O, R 3 , R 4 and R 5 represent each independently of one another a hydrogen atom, a hydroxyl group or a (C 1 -C 12 )alkoxy group, R 6 represents a hydrogen atom, a (C 1 -C 12 )alkyl group, a group —(CH 2 ) n NR 7 R 8 or a group —(CH 2 ) n N + R 7 R 8 R 9 where n=1 to 12, R 7 and R 8 represent each independently of one another a hydrogen atom; a cyano; (C 1 -C 4 )alkyl; aryl(C 1 -C 4 )alkyl; aryl(C 1 -C 4 )alkenyl; (C 1 -C 4 )alkyl-carbonyl or arylcarbonyl radical; the alkyl, alkenyl, and aryl radicals being optionally substituted by one or more identical or different radicals selected from halo, hydroxyl, alkoxy, alkylthio, acyl, free, salt-form or esterified carboxyl, cyano, nitro, mercapto or amino radicals, the amino radical being itself optionally substituted by one or more identical or different alkyl radicals; and R 9 represents a hydrogen atom or a cyano, (C 1 -C 4 )alkyl, aryl(C 1 -C 4 )alkyl, aryl (C 1 -C 4 )alkenyl, alkylcarbonyl or arylcarbonyl radical, the alkyl, alkenyl, and aryl radicals being optionally substituted by one or more identical or different radicals selected from halo, hydroxyl, alkoxy, alkylthio, acyl, free, salt-form or esterified carboxyl, cyano, nitro, mercapto or amino radicals, the amino radical being itself optionally substituted by one or more identical or different alkyl radicals; Z represents either two hydrogen atoms or one oxygen atom, and X represents alternatively an oxygen atom or a sulfur atom on an —SO group or an —SO 2 group or a group —NR 6 where R 6 is as defined above or represents an amine-protective group, comprising providing an α,β-ethylenic ketone of formula (10) and oxidizing said ketone to a spirodienone of formula (11) wherein said spirodienone of formula (11) is thereafter transformed to produce a compound of formula (1).