| 摘要 |
PROBLEM TO BE SOLVED: To produce a compound useful as a synthetic intermediate for carbapenem-based compounds useful as an antimicrobial agent at a low cost by suppressing an increase in the waste water load due to by-products in production. SOLUTION: This azetidinone compound of formula I (R<1> is hydroxyl group which may be protected or an alkyl which may be substituted with a halogen; R<2> is H or a readily eliminable amino-protecting group; R<3> is an alkyl which may be substituted; X is a halogen), e.g. (3S,4S)-3-[(1R)-1-t- butyldimethylsilyloxyethyl]-4-[(1R)-1-chloroformylethyl]azetidin-2-one. The compound of formula I is obtained by reacting an azetidinone compound of formula II with a halogenating agent (e.g. phosgene) in the presence of a deacidifying agent (e.g. diisopropylethylamine) or a catalyst (e.g. dimethylformamide). The compound of formula I is reacted with a compound of formula III (R<4> is a carboxy-protecting group) in the presence of an Mg compound to afford a compound of formula IV which is a synthetic intermediate for carbapenem-based compounds. |
