Construction of intermediate 87 Continued 1.DbaH,CH2cCl2-78°C 2. Ph P=CHCO2Et CH2Cl2, 25C TBs (91%0veal) 1.(+H-DET, TI(OA-Pr) OOH, CH2Ch, -20C EtN,CH2Cl2,0°c 3. Ph3P=CH2, THF, 0C OBn 1. TBAF, THF, 25C 2. PPTS, CH2Cl TBs Me2 sotF, 2, 6-lutidine 1.03, CH2Ch,-78 C: then Ph3P, 25C 2. MeMgCl, THF, 0C 3. DMP. CH2Cl2,25℃CTBSO O O O O O H H H H H Me Me H H Me Me Me C D E F G OBn OBn H MeO2C 153 1. Dibal-H, CH2Cl2 , -78 oC 2. Ph3P=CHCO2Et, CH2Cl2 , 25 oC 3. Dibal-H, CH2Cl2 , -78 oC (91% overall) O O O O O O H H H H H Me Me H H Me Me Me C D E F G OBn OBn H TBS HO 154 O O O O O O H H H H H Me Me H H Me Me Me C D E F G OBn OBn H TBS O 155 1. (+)-DET, Ti(Oi-Pr)4 , t-BuOOH, CH2Cl2 , -20 oC 2. SO3 -pyr., DMSO, Et3N, CH2Cl2 , 0 oC 3. Ph3P=CH2 , THF, 0 oC (79% overall) TBSO O O O O O O H H H H H H Me H Me H H Me Me Me B C D E F G OBn OBn H 156 1. TBAF, THF, 25 oC 2. PPTS, CH2Cl2 , 0 oC 3. t-BuMe2SiOTf, 2,6-lutidine CH2Cl2 , 0 oC (76% overall) O TBSO O O O O O O Me H H H H H H Me H Me H H Me Me Me B C D E F G OBn OBn H 157 1. O3 , CH2Cl2 , -78 oC; then Ph3P, 25 oC 2. MeMgCl, THF, 0 oC 3. DMP, CH2Cl2 , 25 oC (91% overall) Construction of Intermediate 87 Continued