Stereoselective conjugate addition of TMSI-activated butylcopper to 1-(R)-endo-(1-naphthyl)bornyl crotonate

Article abstract of DOI:10.1016/0022-328X(90)80182-Y

Conjugate addition of butylcopper/iodotrimethylsilane to naphthylbornyl crotonate (1) at -60 deg C gives 1-<1-(R)-endo-(1-naphthyl)>bornyl <(S)-3-methyl>heptanoate (2) in 93percent yield and 98percent diastereomeric excess.The addition of TMSI-activated butylcopper is faster at -60 deg C than that of lithium dibutylcuprate (LiBu2Cu).