""""""""Boradeoxyribonucleosides"""""""" focuses on two points where boron may replace carbon in deoxyribonucleosides to provide novel compounds which have a good chance of being antiviral agents. First, syntheses of 3-[1-(2- deoxy)ribosyl]-6-borapyrimidines are proposed. 6-Borapyrimidines are the only borapyrimidine isomers which have the boron atom in a hydrolytically stable position. This is a significant series of compounds to test because there are only a limited number of ways in which the pyrimidine ring can be modified so as to interfere with RNA or DNA synthesis. Syntheses of deoxyribonucleoside analogues having boron substituents in the 3-position of the deoxyribose unit are also proposed. These bear a close structural analogy to known anti-HIV-1 agents such as AZT or DDC and would be likely to decouple the crucial enzymatic phosphorylation for nucleotide synthesis. ONce the compounds have been prepared, samples will be submitted for screening against the AIDS virus. Samples will also be screened for anticancer activity, as well as for other antiviral activity. If nontoxic compounds are found, they will be submitted elsewhere for screening as possible agents for the proposed 10B neutron capture tumor therapy.