Trimethylaluminum-promoted 1,4-addition reaction of cuprates to six or eight-membered 2-hydroxymethyl enones

1,4-Addition reaction of higher order cyanocuprates such as Ph 2 Cu(CN)Li 2 and [Et 3 SiO(CH 2 ) 3 C(=CH 2 )] 2 Cu(CN)Li 2 (3) to six or eight-membered cyclic 2-hydroxymethyl enones proceeded efficiently by successive treatmentwith trimethylaluminum and cuprate reagents. A side chain for C-ring of 19-hydroxypaclitaxel (1) was introduced in high yields on treating highly functionalized eight-membered cyclic hydroxymethyl enone (2c) with trimethylaluminum and cuprate (3).