Benzcatechinborane → isopropyl 7-{(4R)-4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-en-1-yl]-2-oxo-1,3-oxazinan-3-yl}heptanoate

Participants

Reaction Steps

To a solution of catecholborane (107 mg) in toluene (1 mL) was added (S)-2-methyl-CBS-oxaborolidine (1M in toluene, 0.89 mL) under N2 at −78° C. and the mixture was stirred at the temperature for 1 h. Isopropyl 7-{(4R)-4-[(1E)-4,4-difluoro-3-oxo-4-phenylbut-1-en-1-yl]-2-oxo-1,3-oxazinan-3-yl}heptanoate (200 mg) in toluene (2 mL) was added via a cannula slowly and the mixture was stirred for an additional hour and quenched with 1N HCl. The mixture was allowed to warm to room temperature and extracted with DCM (2×). The organic layers were dried over Na2SO4 and filtered. The filtrate was concentrated in vacuo and the residue purified by column chromatography (80-100% ethyl acetate/hexanes) to give the title compound. MS (+ESI): m/z 454 (M+1)+.

Provenance & Evidence