Stereodefined Substituted Cyclopropyl Zinc Reagents from Gem-Bismetallics

Article abstract of DOI:10.1021/jo00113a032

1,1- or n,n-Bismetallic reagents bearing a methoxymethyl ether in the γ position undergo cyclization at room temperature to give monometalated, diastereoselectively substituted cyclopropanes.The nature of the substituents is crucial for this diastereoselection, a ?-chelation between one metal and a properly located unsaturation, as well as 1,2-strain, are proposed to explain the steric outcome of these reactions.