Synthesis of Higher α-Chlorovinyl and α-Bromovinyl Amino Acids: The Amino Protecting Group Determines the Reaction Course

Authors

David B. Berkowitz, University of Nebraska - LincolnFollow
Michelle L. Pedersen, University of Nebraska - Lincoln
Wan Jin Jahng, University of Nebraska - Lincoln

Date of this Version

6-17-1996

Citation

Tetrahedron Lett. 1996 June 17; 37(25): 4309–4312. doi:10.1016/0040-4039(96)00832-5.

Comments

Copyright (c) 1996 Elsevier Inc. Used by permission.

Abstract

N-Trifluoroacetyl α-vinyl amino esters are smoothly converted to the corresponding α-chlorovinyl or α-bromovinyl amino esters through the agency of phenyselenyl chloride or phenylselenyl bromide, respectively, followed by oxidation and pyrolysis. Exclusively the (E)-extemal halovinyl isomer and the internal halovinyl isomer are observed. The amino protecting group is a critical determinant of the reaction course (alkene addition vs. 5-exo-trig-like cyclization).