ORGN 475

A tert-butyl-6-iodomethyl-[(4R,6S)-2-oxo-[1,3]dioxan-4-yl]acetate 2, an advanced precursor of Statins hyperlipidemic agents as HMG-CoA reductase inhibitor, was stereoselectively synthesized from 'carbamate or carbonate synthon 1' through the intramolecular iodocyclization. The iodine-induced electrophilic cyclization of homoallylic carbamate or t-butyl carbonate (1) in mild condition was significantly afforded diastereoselectivity. The use of catalyst(AgOTf or NaI) and polar solvents were enhanced reactivity without reducing stereoselectivity. As illustrated in Scheme, the resultant six-membered iodo acetonide 3 is useful intermediate which readily derivable alcohol, aldehyde, phosphonateornitrile group.