A new synthesis of 3-substituted-1H-indenes through reaction of o-(β-magnesioalkyl)phenylmagnesium dihalides with carboxylate esters

A new synthesis of 3-substituted-1H-indenes has been developed through the reaction of o-(β-magnesioalkyl)phenylmagnesium dihalides with carboxylate esters, followed by dehydration of the intermediate 1-substituted-1-indanols. Di-Grignard reagents allowing the synthesis of 3-substituted-, 2-methyl-3-substituted-, and 4-methyl-3-substituted-1H-indenes have been prepared, with overall yields for the two-step sequence ranging from 45 to 95%.