REACTIONS OF CARBONYL-COMPOUNDS WITH BENZYL CHLOROMETHYL ETHER OF DIIODOMETHANE IN THE PRESENCE OF SAMARIUM(II) IODIDE OR METALLIC SAMARIUM - NEW ROUTES TO 1,2-DIOLS, IODOHYDRINS AND CYCLOPROPANOLS

Carbonyl compounds react with benzyl chloromethyl ether in the presence of samarium(II) iodide to afford the corresponding addition products which, when subsequently hydrogenolysed, yield 1,2-diols. Simple aldehydes and ketones react with diiodomethane in the presence of samarium metal to give iodohydrins in good yields. Under similar reaction conditions, alpha-halogeno substituted ketones and aromatic 1,4-diketones are converted into cyclopropanols. These cyclopropanations have been shown to proceed through the initial generation of samarium enolates, followed by the Simmons-Smith type reaction. A novel transformation of esters to cyclopropanols via tandem one-carbon homologation is also described.