Azetidinone intermediates for cephalosporin analogs
申请人:Shionogi & Co., Ltd.
公开号:US04592865A1
公开(公告)日:1986-06-03
Intermediates of the following formula are useful for the synthesis of 1-oxacephalosporins. Their preparation from penicillins and the transformation process to make 1-oxacephalosporins are disclosed. The compounds are of the formula: ##STR1## wherein A is amino or a selected acylamino; COB is carboxy or a selected protected-carboxy; X is halogen or the group OR in which R is a group represented by following formulas: ##STR2## wherein Nu is a selected nucleophilic group; R.sup.1 is a group of the following formula: ##STR3## in which Hal is halogen or alkylsulfonyloxy and R.sup.2 is alkyl or aryl; and Y is hydrogen or methoxy; with the proviso that when R is propargyl or 2-oxopropyl and R.sup.1 is ##STR4## A is in the 3.alpha.-configuration and Y is 3.beta.-hydrogen or A is in the 3.beta.-configuration and Y is 3.alpha.-methoxy.