Reagents and Conditions. a) tert-Butylchlorodiphenylsilane, imidazole, DMAP, an. CH2Cl2, 93%; b) DIBAL-H, an. THF, 82 %; c) Methanesulfonyl chloride, triethylamine, an. CH2Cl2, 96%; d) NaI, 65 °C, an. 1,4-dioxane, 95%; e) Triethylphosphite, 94%; f) TBAF, THF, 88%.