Novel 1,3,4-trisubstituted 2-azetidinone derivatives useful as intermediates for the synthesis of beta-lactams and their asymmetric synthesis methods

摘要

Compounds of formula I, consisting of the combination of formulae IA and IB: IMAGE in which: R1 denotes a hydrogen atom, a halogen atom, an alkyl radical, a trifluoromethyl radical, an alkoxy radical, a phenyl or benzyl radical (which are optionally substituted), a benzyloxy radical, a cyano radical, an alkoxycarbonyl radical, a carboxyl radical or an alkylamino radical, R2, different from R1, denotes a hydrogen atom, a halogen atom, an alkyl radical, a trifluoromethyl radical, an alkoxy radical, a phenyl or benzyl radical (which are optionally substituted), a benzyloxy radical, a cyano radical, an alkoxycarbonyl radical, a carboxyl radical or an alkylamino radical, each R3 denotes an alkyl radical or the two R3s form together and with the atoms of the dithioacetal functional group to which they are attached a 5- to 7-membered ring, R4 denotes an optionally substituted phenyl radical, a naphthyl radical or a furyl radical, each of R5 and R6, which are identical or different, denotes a hydrogen atom, an alkyl radical or an aryl radical (optionally substituted), and each R7 denotes a methyl radical or the two R7s form together and with the carbon atom to which they are attached a cyclohexane nucleus or a cyclopentane nucleus. The compounds of formula IA and IB are intermediates which are useful for the preparation of compounds of formulae XA and XB: Original abstract incomplete.