A degassed solution of ((1R,2R,3R)-3-(3-(benzyloxy)benzyl)-2-((S)-3-(tert-butyldimethylsilyloxy)octyl)-4-methylenecyclopentyloxy)(tert-butyl)dimethylsilane (0.75 g, 1.15 mmol) in 8 ml dry THF was cooled to 0° C. under nitrogen, and 9-borabicyclo[3,3,1]nonane (6.9 ml, 0.5M in THF) was dropwise added to the mixture. The colorless solution was stirred for overnight at 0° C. and treated with 30% hydrogen peroxide (3 ml) followed by 3N potassium hydroxide (3 ml). The resulting suspension was stirred for one hour at room temperature. The mixture was extracted with EtOAc, and the organic layer was washed with 20 ml brine, dried over MgSO4, and evaporated. The resulting residue was purified by chromatography on a silica gel column using hexane-EtOAc as eluent to give the titled compound: 0.6 g (yield 78%)
