NaHMDS (10.01 mL, 10.01 mmol) as a solution in THF was added to (6-ethoxycarbonyl-hexyl)-triphenyl-phosphonium bromide I (10.54 mmol) in THF (40 mL) at −78° C. under Ar(g). After 30 min, di-pyridin-2-yl-methanone (1437 g, 7.81 mmol) in THF (5 mL) was added; the reaction was stirred for 2 h, and was then allowed to warm to rt. After 17 h, saturated aqueous NH4Cl (250 mL) and EtOAc (150 mL) were added; the phases were separated, and the aqueous phase was extracted with EtOAc (2×100 mL). The organic phases were combined, dried over MgSO4, filtered, and then evaporated under reduced pressure. The resulting residue was purified by silica gel column chromatography eluting with CH2Cl2/MeOH (100:0.5 to 100:2) to furnish II as a pale brown oil (990 mg, 40%).
