Methyl acetoacetate → 4-Hydroxy-6,6-diphenethyl-5,6-dihydro-pyran-2-one

Participants

Reaction Steps

Freshly distilled THF (25 mL) was cooled in an ice bath under a nitrogen atmosphere, then charged with 660 mg (16.5 mmol) sodium hydride (60% dispersion). This suspension was treated with 1.89 g (16.3 mmol) methyl acetoacetate dropwise, and the reaction was stirred for 10 minutes. n-Butyllithium (10.3 mL of 1.6M in hexanes; 16.5 mmol) was dripped in and the reaction was stirred 30 minutes. At this time 3.10 g (13 mmol) of 1,5-diphenyl-3-pentanone (Ram and Spicer, Tetrahedrom Lett., 1988, 29 (31), 3741) in 20 mL THF was added dropwise over 15 minutes. After 4 hours 100 mL H2O was added and the reaction stirred overnight. The reaction was extracted with diethyl ether, and the organics set aside. The aqueous layer was chilled, treated with 50% HOAc until a precipitate formed, and then extracted with EtOAc. These organics were washed with saturated brine, dried (Na2SO4), and concentrated. 1H NMR (DMSO-d6) δ 2.0 (d of d, 4 H), 2.65 (m, 6 H), 5.0 (s, 1 H), 7.15-7.35 (m, 10 H), 11.4 (bs, 1 H).

Provenance & Evidence