Synthesis of enantiopure 1-azaspiro[4.5]dec-6-en-8-ones from L-proline derivatives

An enantioselective synthesis of protected 1-azaspiro[4.5]dec-6-en-8-one derivatives was achieved using an alkylidene carbene 1,5-CH insertion reaction as the key step. (c) 2006 Elsevier Ltd. All rights reserved.