Diethylchlorophosphite-cyanoborane (1) was prepared in 65% yield by the rea
ction of sodium cyanoborohydride and bromine followed by refluxing with die
thylchlorophosphite. Compound 1 was reacted further with several commercial
ly available nucleosides to give substituted boranonucleic acids in 46-91%
yields. (C) 2001 Elsevier Science B.V. All rights reserved.