Synthesis 2003(16): 2483-2486  
DOI: 10.1055/s-2003-42415
PAPER
© Georg Thieme Verlag Stuttgart · New York

Synthesis of N-Protected 3,3-Difluoroazetidin-2-ones

Simon Lacroix, Arnaud Cheguillaume, Stéphane Gérard, Jacqueline Marchand-Brynaert*
Unité de Chimie Organique et Médicinale, Université catholique de Louvain, Bâtiment Lavoisier, Place Louis Pasteur 1, 1348 Louvain-la-Neuve, Belgium
Fax: +32(10)474168; e-Mail: Marchand@chim.ucl.ac.be;
Further Information

Publication History

Received 21 July 2003
Publication Date:
29 September 2003 (online)

Abstract

Representative N-protected 3,3-difluoroazetidin-2-ones 3 were obtained, either in one step by cycloaddition of zinc enolate 1 derived from ethyl bromodifluoroacetate onto N,N′,N′′-trisubstituted hexahydro-1,3,5-triazines 2 (Schiff base trimer) in the case of 3a [N-(p-methoxybenzyl) derivative], or in two steps consisting of a Reformatsky-type reaction for the preparation of N-substituted 3-amino-2,2-difluoropropanotes 8 followed by N1-C2 cyclization under basic conditions in the cases of 3b (N-anisyl derivative) and 3c (N-benzhydryl derivative).