PROCESS FOR THE PREPARATION OF CHIRAL 4-ARYLOXYAZETIDINONES
摘要
A process for preparing a single enantiomer of a 4-aryloxyazetidin-2-one derivative in optically pure form comprises reacting a hindered vinyl ester with chlorosulphonyl isocyanate: displacing the hindered acyloxy group with a phenolic derivative containing a protected carboxy group; deprotecting the carboxylate moiety: resolving with a chiral amine; filtering: and regenerating the desired enantiomer by acidification. A method for enriching the product obtained from the acyloxy displacement step in favour of the desired enantiomeric form, by treating with an asymmetric catalyst such as a chiral alkaloid derivative, is provided: as also is a method for racemising the unwanted antipode of the desired 4-aryloxyazetidin-2-one enantiomer. The invention further provides novel enantiomers based on the 4-aryloxyazetidin-2-one ring structure.
申请公布号
CA2061577(A1)
申请公布日期
1992.08.22
申请号
CA19922061577
申请日期
1992.02.20
申请人
ASHWOOD, MICHAEL S.;BISHOP, BRIAN C.;HOUGHTON, PETER G.;HUMPHREY, GUY R.
发明人
ASHWOOD, MICHAEL S.;BISHOP, BRIAN C.;HOUGHTON, PETER G.;HUMPHREY, GUY R.