Addition of Water to Alkenes: Hydroboration --一 Addition of a B-H bond of borane (BH3)to an alkene to give an organoborane Borane An organoborane BHa is highly reactive;is electron deficient;is a H Lewis acid H Reaction occurs with syn H stereochemistry Borane THF BH3-THF complex H OH CH3 BH3 -0H H THF CH3 H202 CHg 1-Methylcyclopentene Alkylborane trans-2-Methylcyclopentanol intermediate (85%) 2004 Thomson-Brooks/Cole Addition of Water to Alkenes: Hydroboration „ Addition of a B-H bond of borane (BH 3) to an alkene to give an organoborane „ BH3 is highly reactive; is electron deficient; is a Lewis acid „ Reaction occurs with syn stereochemistry