Step 1: Preparation of (R)-acetic acid-1-(pyridin-2-yl)-ethyl ester
At room temperature, (R)-1-(pyridin-2-yl)-ethanol (21.2 mmol), 4A molecular sieve powder (3 g), vinyl acetate (6 mL), and lipase Candida Antarctica acrylic resin (0.87 g) were stirred overnight in i-Pr2O (40 mL). The solid residue was removed by filtration.
Volatile substances were evaporated and purified by chromatography, eluting with hexane/EtOAc (7:3 to 1:1) to give a rapidly eluting colorless oily (R)-acetic acid-1-(pyridin-2-yl)-ethyl ester (50%).
Step 2: Preparation of (R)-2-(1-hydroxyethyl)pyridine
(R)-acetic acid-1-(pyridin-2-yl)-ethyl ester (9.620 mmol) was dissolved in methanol (50 mL), and then a solution of potassium carbonate (38.48 mmol) in water (10 mL) was added. The mixture was stirred at ambient temperature for 4 hours. It was diluted with brine, extracted three times with EtOAc, dried over anhydrous Na2SO4, filtered through a short silica gel pad, and concentrated under vacuum to give the desired intermediate (R)-2-(1-hydroxyethyl)pyridine as a colorless oily substance (89%).
