Studies towards the large scale chemical synthesis of the precursors of ribonucleosides-3',4',5',5''-2H4 and -2',3',4',5',5''-2H5.

A summary delineating the large scale synthetic studies to prepare labeled precursors of ribonucleosides-3',4',5',5''-2H4 and -2',3',4',5',5''-2H5 from D-glucose is presented. The recycling of deuterium-labeled by-products has been devised to give a high overall yield of the intermediates and an expedient protocol has been elaborated for the conversion of 3-O-benzyl-alpha,beta-D-allofuranose-3,4-d2 6 to 1-O-methyl-3-O-benzyl-2-O-t-butyldimethylsilyl-alpha,beta-D-ribofuranose-3,4,5,5'-d4 16 (precursor of ribonucleosides-3',4',5',5''-2H4) or to 1-O-methyl-3,5-di-O-benzyl-alpha,beta-D-ribofuranose-3,4,5,5'-d4 18 (precursor of ribonucleosides-3',4',5',5''-2H4).