Triisopropyl borate → (1S,2RS)-4-[2-(tert-butyldimethylsilanyloxy)-1-methyl-4-pyridin-3-ylbutoxy]benzeneboronic acid

Participants

Reaction Conditions

Reaction Steps

A solution of tert-butyllithium (2.5 ml, 1.7M in hexanes) was added over a 1 hour period to a solution of (2S,3RS)-2-(4-bromophenoxy)-3-tert-butyldimethylsilyloxy-5-pyridin-3-ylpentane (1.60 g, Example 5b)) and triisopropylborate (1.07 ml) in tetrahydrofuran (25 ml) at −78° C. The resulting solution was stirred at −78° C. for 2 hours and was then quenched by the addition of a saturated solution of ammonium chloride in water (50 ml). The mixture was poured into water (50 ml) and extracted into ethyl acetate (2×50 ml). The combined extracts were dried over anhydrous magnesium sulfate, filtered and concentrated. The residue was purified by chromatography on silica eluting with ethyl acetate and then ethyl acetate:methanol (4:1) to afford the sub-title compound as a foam (1.2 g).

Provenance & Evidence