Preparation of optically active 3-substituted azetidinones of the formula (I) ##STR1## in which R.sup.1 is a hydroxy-protective group wherein an allylic alcohol of the formula (II) ##STR2## is acylated, then subjected to asymmetric enzymatic hydrolysis yielding the R-allylic alcohol. The hydroxyl group is protected and then stereoselectively reacted with an amine which is subsequently cyclized to yield the desired 3-substituted azetidinone. Two new species of microorganisms have been isolated, Pimelobacter sp. No. 1254 and Bacillus megaterium No. 1253 which exhibit stereoselective esterase activity.
公式(I)中的光学活性3-取代
氮杂环酮的制备##STR1##其中R.sup.1是一个羟基保护基,其中
烯丙醇的公式(II)##STR2##被酰化,然后经过不对称酶催化
水解产生R-
烯丙醇。羟基被保护,然后与随后环化的胺立体选择性地反应,以产生所需的3-取代
氮杂环酮。已经分离出两种新的微
生物物种,Pimelobacter sp. No. 1254和Bacillus megaterium No. 1253,它们表现出立体选择性
酯酶活性。