PURPOSE: To obtain an intermediate having desired stereochemical property useful for the synthesis of 1-β-methyl-carbapenem antibiotic by condensing azethidinone with Z-enolate containing asymmetric 2-thia- or oxazolidino part.
CONSTITUTION: A compd. expressed by formula I is allowed to react with a asymmetric enolate expressed by formula II in a solvent in the presence of an org. base and a Lewis acid catalyst to obtain a compd. expressed by formula III. In the formula I, R2, R9 are H, 1 to 4C straight-chain, branched-chain or cyclic alkyl which may have substituents (F, OH, protected OH), but both are not unsubstd. alkyl oat one time; R3 is H, a protecting group which is easily removed; L is a leaving group. In the formula II, X1, X2 are O, S; R1 is 1 to 4C alkyl or alkoxy; R4 to R6 are H, 1 to 4C alkyl, 7 to 10C aralkyl, 6 to 10C alkyl, 7 to 10C alkalyl (OH, OR10, SH, SR10; R10 is 1 to 4C alkyl) but R4 is not same as R5; R8 is an enol protecting group which is easily removed. The compd. of the formula III is converted into a compd. expressed by formula IV by treating in a solvent under basic hydrolytic conditions.
TOOMASU ENU ZARUTSUMAN
RERIA EMU FUENTESU
