4-Norbornyl-sulfonyl azetidinone intermediates and process for preparing (S)-3-acylamino-4-substituted-2-azetidinones

摘要

Compounds having the formula <IMAGE> can be prepared by reacting a compound having the formula <IMAGE> with a Grignard reagent having the formula R3-Mg-X1 , wherein R1 is phenylacetyl or phenoxyacetyl; R2 is a not readily enolyzable alkyl group, aryl or norbornyl; R3 is alkyl, alken-1-yl, alkyn-1-yl, 2-phenylethenyl, 2-phenylethynyl, aryl or arylalkyl; X1 is bromine or chlorine. (3R-cis)-3-Acylamino-4-norbornylsulfonyl-2-azetidinones are novel compounds that form an integral part of this invention.