Diastereoselective Formation of Cyclopropanation from α,β-Epoxy Ketones

Significance

Hydroxycyclopropanes were formed by a diastereoselective addition of bis(iodozincio)methane to the carbonyl group of α,β-epoxy ketones, followed by a stereospecific S_N2 epoxide ring opening with inversion of the stereogenic center. Excellent diastereoselectivity was obtained with no loss of enantiomeric excess if enantioenriched epoxides were used. Under the same conditions, ring-fused epoxides (when R² and R⁴ are tethered) gave spiro-bicycles in good but diminished dr.