Approaches to ,4-dioxo-5-methyl-1(2H)-pyrimidinyl-D-arabinitol, and t
he related uracil derivative, have been developed. These conceptually
new, optically active analogs of AZT, derived from 1,4-anhydro-D-ribit
ol, are among the first examples of regioisomeric analogs of AZT.