2′-O-Me-oligoribonucleotides bearing a stereoregulated boranophosphate backbone (2′-O-Me-PB-ORNs) were synthesized by using 2′-O-Me-ribonucleoside 3′-O-oxazaphospholidine monomers. A thermal denaturation study of the resultant diastereopure 2′-O-Me-PB-ORNs revealed that an all-(Sp)-boranophosphate backbone had a large stabilizing effect on the duplex with complementary RNA.