| 摘要 |
PURPOSE:To stereospecifically obtain the title compound useful as an intermediate for producing antifungally active beta-lactam compounds by using a 2-(1- hydroxyethyl)acrylic ester as starting material. CONSTITUTION:Firstly, a compound of formula I (R<2> is protected carboxyl group) is acylated using an organic acid or its reactive derivative to form a compound of formula II (R is acyl). Second, this compound is put to enzymatic hydrolysis in the presence of an esterase, pref. lipase stemmed from Pimelobacter sp. or Bacillus sp. to form a compound of formula III. Third, a hydroxy-protective group is introduced into this compound into a compound of formula IV (R<1> is hydroxy-protective group), which is then put to stereoscopically selective addition reaction of a compound of formula R<3>-NH2 (R<3> is H or amino-protective group) or its salt to form a compound of formula V. This compound is then cyclized and, if desired, is freed from the amino-protective group, thus obtaining the objective compound of formula VI. |
