Lewis Acid-Mediated Reactions of Alkyl Azides with α,β-Unsaturated Ketones
作者:D. Srinivasa Reddy、Weston R. Judd、Jeffrey Aubé
DOI:10.1021/ol0355130
日期:2003.10.1
[reaction: see text] Alkyl azides react with saturated ketones upon treatment with Lewisacids to afford ring-expansion products through the azido-Schmidt reaction, but this reaction does not proceed when alpha,beta-unsaturated ketones are used. In this study, alkyl azides were reacted with enones in the presence of Lewisacids to give enaminones (vinylogous amides), which formally involve a ring contraction
Abstract Photocyclization of N-arylenamides 10, 15 and 16 led efficiently to spirotricyclic δ-lactams 5, 6 and 7. Compound 7 was easily and stereospecifically transformed in two steps into spirocyclohexylisoquinolines 3 and 4 which show structural analogies with some Amaryllidaceae alkaloids, galanthamine 1 and lycoramine 2.