Reactions of a ‘myrcene–magnesium’ complex with aldehydes, ketones, epoxides, carbon dioxide, and acetonitrile

Abstract

A ‘myrcene–magnesium’ complex has been prepared by the reaction of myrcene (7-methyl-3-methyleneocta-1,6-diene) with magnesium in the presence of iron(III) chloride and ethyl bromide. Reactions of this complex with aldehydes, ketones, and epoxides yielded mixtures of alcohols by attack at the 2- and 3-positions of the original 1,3-diene unit. Similarly, reactions of the complex with carbon dioxide and acetonitrile gave carboxylic acids and ketones, respectively. The exact nature of these additions is not well understood but steric factors are important in determining product distributions. Some information on the nature of the magnesium complex has been obtained by a study of the hydrocarbons produced by acidic hydrolysis of the ‘myrcene–magnesium’ complex and the analogous derivatives of trans,trans-1,4-diphenylbuta-1,3-diene.