| 摘要 |
PURPOSE:To industrially advantageously obtain the title compound as an intermediate for carbapenem antibiotics by oxidation of a specific 2-azetidinone derivative as starting material followed by reaction with a halogenating agent and then, if needed, esterification and then dehalogenation. CONSTITUTION:Firstly, a compound of formula I (R<1> is protective group for OH; Z is H or protective group for NH2) is oxidized using an oxygen-contg. gas in the presence of a catalyst such as platinum-active carbon to form a compound of formula II. Second, this compound, if needed, after protecting the carboxyl group in its 4-site side chain, is reacted with a halogenating agent (e.g. thionyl chloride, phosphorus pentoxide) in an appropriate solvent pref. at 20-70 deg.C to form a compound of formula VI (X is halogen; Y<1> is halogen or OR<2> (R<2> is H or protective group for carboxyl group). This compound, when Y<1> is halogen, is esterified as the case may be, followed by dehalogenation, thus obtaining the objective compound of formula IV [Y<2> is OR<3> (R<3> is R<2> or ester residue) or SR<4> (R<4> is ester residue)]. |
