Construction of intermediate 87 Continued tBui,Et20.-120t-78% 0、№e入日oBn then(2-thienyl)(CN)CuLi Et20: THF: HMPA(1: 1: 1 ): then102.780c(85%) (2.4: 1 mixture of stereoisomers in favor of 146) Tfo PPTS, DME, H20, °,(ca.100%) H3 THF, THF,0C H Me o Me H oBn BH then NaOH, H202, 0C Me E OBn 2. LiOH, MeOH, H2O (73% overa 2,46-C13C6H2COC, then 4-DMAP PhH. 80oC (85%0) 100-BConstruction of Intermediate 87 Continued H 102 MeO Me H O F OBn H Me G O OBn TfO E 103 t-BuLi, Et2O, -120 to -78 oC; then (2-thienyl)(CN)CuLi Et2O:THF:HMPA (1:1:1); then 102, -78 oC (85%) O O O O O OBn OBn Me Me H H H Me Me Me O E F G I O O Me Me O 146 (2.4:1 mixture of stereoisomers in favor of 146) O O O O O OBn OBn Me Me H H H Me Me Me E F G 147 HO OH 1. BH3-THF, THF, 0 oC; then NaOH, H2O2 , 0 oC 2. LiOH, MeOH, H2O (73% overall) PPTS, DME, H2O, 25 oC, (ca. 100%) O O O OBn OBn Me Me H H H Me Me E F G CO 101 2H 2,4,6-Cl3C6H2COCl, Et3N, THF, 0 oC; then 4-DMAP, PhH, 80 oC (85%) O O O OBn OBn Me Me H H H Me O E F G H H O Me 100-B O O O OBn OBn Me Me H H H Me O E F G H H O 100 Me + D H HO