A SIMPLE ACCESS TO CARBOCYCLIC ANALOGS OF 2-DEOXY-D-RIBOSE HAVING THE3-HYDROXYMETHYLENE MOIETY REPLACED BY HETEROATOMS

di-O-mesyl-4-O-methoxymethylpentan-1.2,4,5-tetrol, a versatile precurs or for subsequent cyclisations with bivalent nucleophiles, was obtaine d in five steps from the easily accessible )-3-hydroxy-5-hydroxymethyl dihydrofuran-2(3H)-one. Using disodium phosphide in DMSO or disodium s elenide in acetone-water, 4S)-2-benzyloxymethyl-4-O-methoxymethylphosp holane and ,4S)-2-benzyloxymethyl-4-O-methoxymethylselenolane were pre pared. The phospholane was oxidized by oxygen (hydrogen peroxide) to g ive the analogous cyclic phospholane oxide (phosphinic acid) which was then transformed with benzyl bromide and alkali carbonate into the 1- benzyl phospholane oxide (phosphinic acid benzyl ester). All heterocyc lic compounds sythesized, formally resemble carba-2,3-dideoxy-D-glycer o-pentofuranose, the carbocyclic analog of 2-deoxy-alpha-D-ribofuranos e.