2,6-Lutidine → HCID 86650529, compound

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 29.7 g (71.9 mmol) of (4S)-4-benzyl-3-{(2R)-2-[(S)-(6-chloropyridin-3-yl)(hydroxy)methyl]hex-5-ynoyl}-1,3-oxazinan-2-one from Step B and 15.0 mL (126 mmol) of 2,6-lutidine in 300 mL of anhydrous dichloromethane at 0° C. under an atmosphere of nitrogen was added 22 mL (94 mmol) of tert-butyldimethylsilyl trifluoromethanesulfonate at a rate slow enough to keep the internal temperature below 3° C. The reaction mixture was stirred for 16 h at 0° C. then evaporated in vacuo to remove all volatiles. The residue was diluted with 400 mL of water and extracted with diethyl ether (3×300 mL). The combined organics were washed sequentially with a 0.5 M aqueous hydrochloric acid solution (100 mL), water (100 mL) brine (100 mL) then dried over magnesium sulfate. After filtration and evaporation in vacuo the residue was purified by silica gel chromatography eluting with a 5-8% ethyl acetate in hexanes gradient to afford the title compound as a colorless foam (37 g, 97%). LC-MS: m/z (ES) 527.3 (MH)+.

Provenance & Evidence