Nucleophilic cyclopropanation reaction with bis(iodozincio)methane by 1,4-addition to α,β-unsaturated carbonyl compounds

Abstract

Treatment of α,β-unsaturated ketones with an electrophilic site at the γ-position in the presence of trimethyl-silyl cyanide with bis(iodozincio)me-thane afforded the (Z)-silyl enol ether of the β-cyclopropyl substituted ketone in good yields. The reaction proceeds by 1,4-addition to form an enolate, and its sequential intramolecular nucleo- philic attack to an adjacent electrophil-ic site. The reaction of γ-ethoxycarbon-yl-α,β-unsaturated ketone and bis(io-dozincio)methane in the presence of trimethylsilyl cyanide afforded 1-ethoxy-1-trimethylsiloxycyclopropane derivatives, which can be regarded as the homoenolate equivalent. Additionally, reaction of the obtained homoenolate equivalents with imines give 1-(E)-alkenyl-2-(1-aminoalkyl)alkanols dia-stereoselectively. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.