ChemInform Abstract: Generation of a Ketocarbenoid from α,α-Dibromodeoxybenzoin by Samarium(II) Iodide and Its Trapping by Alkene Cycloaddition.
Abstract
α,α-Dibromodeoxybenzoin (I) reacts with samarium(II) iodide to form an intermediate ketocarbenoid which is regioselectively trapped with the alkenes (II), forming the dihydrofurans (III).
ChemInform Abstract
α,α-Dibromodeoxybenzoin (I) reacts with samarium(II) iodide to form an intermediate ketocarbenoid which is regioselectively trapped with the alkenes (II), forming the dihydrofurans (III). However, the acyclic δ-methylene ketone (IV) is obtained from (I) and (IIe) as the main product, together with (IIIe). (I) and trans-β-methylstyrene (V) produce the trans-substituted dihydrofuran (VI) when treated with SmI2. Similar reaction of (I) and indene (VII) gives the cis-fused indanofuran derivative (VIII). The compounds (VI) and (VIII) are obtained as the single stereoisomers but only in moderate yields.
