Enantioselective synthesis of 2-ethyl-2,3-dihydrobenzofuran carboxylic acid, direct precursor of (+)-efaroxan, from a Baylis–Hillman adduct
作者:Gabriel P. de Carvalho e Silveira、Fernando Coelho
DOI:10.1016/j.tetlet.2005.07.099
日期:2005.9
We describe herein a new and straightforward enantioselective approach to R-(+)-2-ethyl-2,3-dihydrofuran carboxylic acid, the direct precursor of (+)-efaroxan, an alpha(2) adrenoreceptor antagonist, which is indicated to be used for the treatment of neuro-degenerative diseases (Alzheimer and Parkinson), migraine and type Iota Iota diabetes. Our goal was accomplished using a Baylis-Hillman adduct as starting material. The dihydrobenzofuran acid was obtained in eight steps with an overall yield of 14%. (c) 2005 Elsevier Ltd. All rights reserved.