Vinyl groups in phenyl-terminated polybutadiene (la) containing 99% unsaturation (27% vinyl group, 73% internal olefin), and for which the average M-n is 3400, were simultaneously hydrogenated and hydroacylated with various aromatic or heteroaromatic primary alcohols in the presence of the catalytic system RhCl3.H2O, PPh3 and 2-amino-4-picoline. Sterically less hindered alcohols, such as benzyl alcohol, showed greater reactivity than sterically more hindered alcohols, such as 2-naphthylmethanol and heteroaromatic primary alcohols. Vinyl groups in phenyl-terminated polybutadiene (1b) containing 99% unsaturation (45% vinyl group, 55% internal olefin) and for which the average M-n is 1300 also showed similar reactivity toward various primary alcohols under identical reaction conditions.