A straightforward synthesis of cyclopropanes from aldehydes and ketones

A new synthetic methodology for preparing cyclopropanes is presented. The r eaction involves a cooperative zirconium- and Lewis acid-mediated deoxygena tive coupling of carbonyl compounds with a Grignard reagent. In this way, v arious cyclopropanes are obtained in moderate to excellent yields, directly from saturated, unsaturated, and aromatic aldehydes and ketones. This reac tion tolerates the presence of several different functional groups.