Resolution of trans-2-(alkoxycarbonylethyl)-lactams useful in the synthesis of 1-(4-fluoro-phenyl)-3(R)-(S)-hydroxy-3-(4-fluorophenyl)- propyl-4(S)-(4-hydroxyphenyl)-2-azetidinone

摘要

A process for the microbiological or enzymatic hydrolytic resolution of racemic trans-2-(alkoxycarbonylethyl) lactams of the formula I: ##STR1## wherein R is C.sub.1 -C.sub.7 alkyl, 2,2,2- trifluoroethyl or methoxyethoxyethyl and R.sup.1 is hydrogen or a protecting group is disclosed, whereby an optically enriched compound of the formula Ib or IIa: ##STR2## is obtained.