PURPOSE: To provide Z-enolate having asymmetric 2-thia- or oxazolidinone part used for the stereoselective preparation of an intermediate useful for the synthesis of 1-β-methyl-carbapenem antibiotic.
CONSTITUTION: The compd. is expressed by formula I, wherein 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 aryl, 7 to 10C alkalyl (OH, OR10, SH, SR10; R10 is 1 to 4C alkyl), but R4 is not same as R5. The compd. is, for example, a compd. expressed by formula II. The compd. of the formula II is obtd. by allowing (+)-(4S)-3-(1-oxopropyl)-4-(1-methylethyl)-2-oxazolidinone to react with propionyl chloride to obtain a compd. expressed by formula III, and then allowing the compd. of the formula III to successively react with diethyl boryltrifurilate and with boron etherate trifluroide. By allowing the compd. of the formula to react with a azethidinone compd. expressed by formula IV to obtain a compd. expressed by formula V, and by treating the compd. of the formula V in a solvent under basic hydrolytic conditions, a compd. expressed by formula VI is obtd.
TOOMASU ENU ZARUTSUMAN
RERIA EMU FUENTESU
