| 摘要 |
PURPOSE:To carry out acetoxylation at the 4-position by one stage readily and to produce the titled compound useful as an intermediate for antibiotics, by treating a beta-lactam compound containing a silylether group at the 4-position with a base and acetic anhydride in the presence of an adsorbent. CONSTITUTION:A beta-lactam compound shown by formula I (R1 is OH-protecting group, especially preferably t-butyldimethylsilyl, isopropyldimethylsilyl, etc.; R2-R4 are lower alkyl, phenyl or aralkyl) or treated with a base (preferably methylaminopyridine) and acetic anhydride in the presence of an adsorbent such as alumina, etc., to give a 4-acetoxy-3-hydroxyethylazetidin-2-one derivative [e.g., (3R,4R)-4-acetoxy-3-[(R)-1-t-butyldimethylsilyloxyethyl]azetidin-2-one, etc.,] shown by formula II. USE:An intermediate for synthesizing beta-lactam antibiotic substance of carbapenem type or penem type. |
