Sterically biased 3,3-sigmatropic rearrangement of azides: efficient preparation of nonracemic alpha-amino acids and heterocycles.
[reaction: see text] Homochiral alpha-amino acids, heterocycles, and carbocycles are efficiently constructed via a short sequence of reactions starting from the chiral auxiliary p-menthane-3-carboxaldehyde. The key feature of the sequence is a highly selective tandem Mitsunobu/3,3-sigmatropic rearrangement of hydrazoic acid that procures enantiomerically enriched allylic azides. The sequence is either terminated by oxidative cleavage to provide amino acids or by ring-closing metathesis to provide heterocycles or carbocycles bearing nitrogen.
Gagnon
David
D
Département de Chimie, Université de Sherbrooke, Sherbrooke, QC, Canada J1K 2R1.
Lauzon
Sophie
S
Godbout
Cédrickx
C
Spino
Claude
C