Chloroform → HCID 50941388, compound

Participants

Reaction Conditions

Reaction Steps

Racemic alcohol (±)-18 (68 mg, 0.48 mmol) was dissolved in THF (5 mL) and vinyl acetate (225 μL, 2.4 mmol) was added. Amano lipase PS-30 (30 mg) was added and the resulting suspension was stirred at 15-20° C. The mixture was left stirring for >48 h until around 50% conversion was reached (as seen by NMR). The resulting suspension was diluted with Et2O and filtered on celite, the filter cake rinsed with Et2O. After evaporation of the remaining solvent, the residue was purified by column chromatography using hexanes/EtOAc (5:1, 3:1 then 1.5:1) to yield the desired enantioenriched pyranol (−)-18 (25 mg, 37%). [α]D20 −47.5 (c 1.32, CHCl3). An enantiopurity of 94.1% ee for the alcohol was measured by chiral HPLC analysis of the corresponding activated carbonate 31d: Column ChiralPak IA, 0.7 mL/min, Hexanes/IPA (98:2 to 85:15, from 0 to 45 min), λ=210 nm, T=30° C., Rt minor=22.4 min, Rt Major=23.3 min.

Provenance & Evidence