acetoxyazetidinone 3 to give an adduct 4b in 87% yield with virtually complete β-selectivity which was transformed by simple hydrolysis into the optically pure azetidinone-4-isopropionic acid derivative 5, a key intermediate of 1-β-methylcarbapenems.
使由N-丙酰基-2、2-
二乙基-1、3-苯并恶嗪酮2b生成的烯醇
钠与乙酰氧基氮杂
环丁酮3反应,以87%的收率得到加合物4b,其β-选择性几乎完全,可通过简单
水解转化为加合物光学纯的氮杂
环丁酮-4-异
丙酸衍
生物5(1-β-甲基卡巴南的关键中间体)。