Scheme 9.
Suzuki cross-coupling to access the carbon skeleton of ent-1. Reagents and conditions: a) 9-BBN dimer, THF, 55 °C; b) 39, PdCl2(dppf), aq. Cs2CO3, THF/DMF/H2O, 55 °C; c) TBAF, THF, rt, 26% 42 and 20% 43 from 39.
Suzuki cross-coupling to access the carbon skeleton of ent-1. Reagents and conditions: a) 9-BBN dimer, THF, 55 °C; b) 39, PdCl2(dppf), aq. Cs2CO3, THF/DMF/H2O, 55 °C; c) TBAF, THF, rt, 26% 42 and 20% 43 from 39.