(3R)-4-Acetoxy-3-trimethylsilyl-2-azetidinone, was converted into optically pure benzyl penicillanate in seven steps (22%) using (benzyloxy)nitromethane as a reagent for ring annulation.
(3R)-4-乙酰氧基-3-三甲基甲
硅烷基-
2-氮杂环丁酮用(苄氧基)
硝基甲烷作为环环化试剂,经七个步骤(22%)转化为光学纯的
青霉酸苄酯。