The synthesis of secoribo-nucleoside analogues is described. Compounds 4 and 5 possess interesting antiviral effects in uitro. A procedure is also developed for the conversion of acyclo-uridine nucleoside 7 to a novel derivative of cyclophosphamide 8. Introduction. -Nucleoside analogues have gained increasing importance through their biological activity particularly as antiviral and anticancer compounds [ 11. Recently, a novel acyclic guanine nucleoside analogue, 9-([2-hydroxy-l-(hydroxymethyl)-ethoxylmethy1)guanine (DHPG), was reported independently by several investigators [2-81 to possess antiviral activity comparable to that of 9-[(2-hydroxyethoxy)methyllguanine (acyclovir) [9] [lo].
From another point of view, some specificity has been achieved in the case of the antitumor drug cyclophosphamide ( = 2-[bis(2-chloroethyl)amino]-1 ,3,2,15-oxazaphosphorinan-2-one) [ 111. This drug takes advantage of the fact that in cancer patients there is a higher dephosphorylating activity in the cancer cells than in the normal cells, and hence it will interact to a greater extent with the former.
We, therefore, began a program with the aim of synthesizing a series of purine derivatives (4 and 5) related to the structures of DHPG and acyclovir, thus, allowing an