Méthylhalogénocyclopropanation des éthoxy-alcènes diversement alkylés. Identification stéréochimique des adduits et étude de la stéréosélectivité

Abstract

Ethoxy-alkenes act as excellent carbene acceptors in the methylmonohalogenocyclopropanation reaction mediated by 1,1-dichloroethane and iodide-ion free methyl iodide. As well as chlorinated adducts, a large proportion of brominated products are obtained by means of halogen exchange at the carbene complex – salt intermediate stage. Adduct stereochemistry is determined by 1H and 13C nmr spectroscopy. The syn-stereoselectivity of the reaction is discussed in electronic and steric terms. [Journal Translation]