3′,5′-O-phosphonoalkylidene derivatives of 1-(2-Deoxy-β-D-threo-pentofuranosyl)thymine:: Synthesis and reactivity

Various 3',5'-O-(1-phosphonoalkylidene) derivatives of 1-(2-deoxy-beta-D-threo-pentofuranosyl)thymine bearing a substituent in the omega-position of the alkylidene chain were prepared by the redox reaction of diethyl chlorophosphite with six-membered 3',5'-orthoesters of xylo-dT. Susceptibility of omega-haloalkylidene derivatives for nucleophilic substitution is discussed. The configuration of the final phosphonates was determined by 2D-ROESY NMR experiments. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.