Enantioselective synthesis of alpha,alpha-difluoro-beta-amino acid and 3,3-difluoroazetidim-2-one via the Reformatsky-type reaction of ethyl bromodifluoroacetate with chiral 1,3-oxazolidines

Authors
Marcotte, S Pannecoucke, X Feasson, C Quirion, JC
Citation
S. Marcotte et al., Enantioselective synthesis of alpha,alpha-difluoro-beta-amino acid and 3,3-difluoroazetidim-2-one via the Reformatsky-type reaction of ethyl bromodifluoroacetate with chiral 1,3-oxazolidines, J ORG CHEM, 64(23), 1999, pp. 8461-8464
Citations number
19
Categorie Soggetti
Chemistry & Analysis","Organic Chemistry/Polymer Science
Journal title
JOURNAL OF ORGANIC CHEMISTRY
ISSN journal
00223263 → ACNP
Volume
64
Issue
23
Year of publication
1999
Pages
8461 - 8464
Database
ISI
SICI code
0022-3263(19991112)64:23<8461:ESOAAA>2.0.ZU;2-9
Abstract
Chiral oxazolidines 2a-e can be diastereoselectively alkylated with BrCF2CO 2Et to furnish 3,3-difluoroazetidin-2-ones 3a-e with up to 99% de. Selectiv e cleavage of the chiral appendage provided the corresponding unsubstituted azetidinones. Formation of optically pure a,a-difluoro-P-amino acids 5a-c can be achieved by acidic hydrolysis of N-vinyl-azetidin-2-ones.