Synthesis of 2-azaspiro[4.4]nonan-1-ones via phosphine-catalysed [3+2]-cycloadditions

Authors

Sarah Yong, University of WollongongFollow
Morwenna C. Williams, University of WollongongFollow
Stephen G. Pyne, University of WollongongFollow
Alison T. Ung, University of WollongongFollow
Brian W. Skelton, University of Western Australia
Allan H. White, University of Western Australia
P. Turner, University of Sydney

RIS ID

13288

Publication Details

Yong, S. R., Williams, M. C., Pyne, S. G., Ung, A. T., Skelton, B. W., White, A. H. & Turner, P. (2005). Synthesis of 2-azaspiro[4.4]nonan-1-ones via phosphine-catalysed [3+2]-cycloadditions. Tetrahedron, 61, 8120-8129.

Abstract

The phosphine-catalysed [3+2]-cycloaddition of the 2-methylene γ-lactams 4 and 5 and the acrylate 6 with the ylides derived from the ethyl ester, the amide or the chiral camphor sultam derivative of 2-butynoic acid (7a-c) give directly, or indirectly after reductive cyclization, spiro-heterocyclic products. The acid 32 underwent Curtius rearrangement and then acid hydrolysis to give two novel spiro-cyclic ketones, 41 and 42.