Prodn. of penem antibiotics

摘要

Prodn. of penem cpds. of formula (I) is effected by reacting a 4-acylthio-1-oxalyl-2-azetidinone of formula (II) with a phosphonite diester of formula (III). R1 = H, 1-4C alkyl, 1-12C alkoxy, 1-12C alkylthio, OAr, Ar, 3-6C cycloalkyl, 3-6C cycloalkyloxy, 5-6C oxacycloalkyl (opt. mono- or diunsatd.), 3-6C oxocycloalkyl, gem-di(1-3C)alkoxy(3-6C)cycloalkyl, (1-3C)alkylimino(3-6C)cycloalkyl, arylimino(3-6C)cycloalkyl, hydroxyimino(3-6C)cycloalkyl or (1-3C) alkoxyimino(3-6C)cycloalkyl, where the cycloalkyl gps. are opt. mono- or diunsatd. and opt. mono- or disubstd. by 1-3C alkyl, 1-3C alkoxy, halogen or methylene; Ar = phenyl opt. substd. by 1 or 2 of COOH, 2-5C alkoxycarbonyl, allyloxycarbonyl, CONH2, 1-4C alkylcarbamoyl, CN, F, Cl and/or Br; R2 = H or a protecting gp. removable by hydrolysis, photolysis, oxidn., redn. or enzyme treatment; R3 = H, 1-4C alkyl, 2-4C alkenyl, 1-4C alkoxy, 4-7C cycloalkyl, phenyl, 2-oxo-1,3-dioxolyl, triazolyl, thiazolyl, NH2 or acylamino (N.B., in all exemplified cpds., R3 is O-protected 1-hydroxyethyl); R6 = 1-4C alkyl or phenyl opt. substd. by 1-3C alkyl or 1-3C alkoxy; R4 and R5 = 1-4C alkyl, allyl, benzyl or phenyl opt. substd. by 1-3C alkyl or 1-3C alkoxy.