The conversion of alkynes into substituted cyclopropanes effected by CH2I2-R3Al (R = Me, Et, i-Bu)

The reaction of mono- and disubstituted alkynes with CH2I2-R3Al (R = Me, Et, i-Bu) was studied. It was found that the reaction of alkynes with CH2I2 in the presence of Me3Al gives β-iodoethyl-substituted cyclopropanes. The use of Et3Al or i-Bu3Al affords exclusively cyclopropylic organoaluminum compounds.