Potassium Carbonate → 2(R)-(3-chloro-4-methanesulfonyl-phenyl)-3-cyclopentyl-N-[5-(2(S),3-dihydroxy-propyl)-pyrazin-2-yl]-propionamide

Participants

Reaction Conditions

Reaction Steps

A yellow solution of potassium ferricyanide (1.00 g, 3.037 mmol), potassium carbonate (430.0 mg, 3.111 mmol), and (DHQ)2PHAL (19.0 mg, 0.0244 mmol) in tert-butyl alcohol/water (16.0 mL, 1:1) was cooled to 0° C. and then treated with a 0.2M solution of osmium tetroxide in toluene (0.048 mL, 0.0096 mmol) followed by the N-(5-allyl-pyrazin-2-yl)-2(R)-(3-chloro-4-methanesulfonyl-phenyl)-3-cyclopentylpropionamide (446.0 mg, 0.996 mmol). The reaction mixture was stirred at 0° C. for 4 h. The reaction mixture was then diluted with ethyl acetate and sodium metabisulfite (0.45 g, 2.37 mmol) and allowed to warm to 25° C. where it was stirred for 15 min. The mixture was then diluted with a saturated aqueous sodium chloride solution and water and extracted with ethyl acetate. The combined organic layers were dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. Biotage chromatography (FLASH 40M, Silica, 2/3 hexanes/ethyl acetate to ethyl acetate) afforded 2(R)-(3-chloro-4-methanesulfonyl-phenyl)-3-cyclopentyl-N-[5-(2(S),3-dihydroxy-propyl)-pyrazin-2-yl]-propionamide (370.2 mg, 77.1%) as a white foam: mp 61–65° C. (foam to gel); (ES)+-HRMS m/e calcd for C22H28ClN3O5S (M+H)+ 482.1511, found 482.1516.

Provenance & Evidence