Highly efficient synthesis of oligodeoxyribonucleotides using alpha-phenyl cinnamoyl group for selective amino protection.

alpha-phenyl cinnamoyl (alpha-PhCm) group has been found to be highly selective for exocylic amino function of all the three deoxynucleosides viz, 2'-deoxyadenosine, 2'-deoxyguanosine and 2'-deoxycytidine. The stereospecific nature of the group confers stability to the N-protected derivatives of 2'-deoxyadenosine and 2'-deoxyguanosine towards acids thereby minimising depurination. The easy preparation and introduction of the group, stability of the protected monomers, milder conditions for deprotection resulting in negligible side products during synthesis and above all hydrophobicity of the group are the additional advantages.