Ammonium Chloride → HCID 18349870, compound

Participants

Reaction Steps

A solution of 2-acetyl-5,6,7,8-tetrahydro-5,5,8,8-tetramethylnaphthalene (33, 4.60 g, 20.0 mmol) and methyl diethylphosphonoacetate (7.33 g, 34.9 mmol) in anhydrous toluene (80 mL) was treated dropwise via syringe with sodium methoxide (25 wt % in methanol, 5.5 mL, 24.0 mmol) at room temperature under argon. The reaction mixture was stirred for 14 h and then poured into a separatory funnel containing diethyl ether and saturated ammonium chloride solution. The layers were agitated and separated, and the organic layer was washed with saturated sodium chloride solution, dried over anhydrous magnesium sulfate, filtered, and concentrated to afford 6.5 g of a pale yellow oil. Purification by column chromatography (20:1 ratio silica gel/crude product; elution with 10% ethyl acetate/hexanes) gave 4.10 g (72%) of 34 as a clear, colorless oil. 1H NMR (300 MHz, CDCl3) δ7.40 (d, J=2 Hz, 1H, ArH), 7.30 (d, J=7 Hz, 1H, ArH), 7.25 (dd, J=2, 8 Hz, 1H, ArH), 6.15 (br s, 1H, C=CH), 3.75 (s, 3H, CO2CH3), 2.58 (s, 3H, CH3C=C), 1.67 (s, 4H, CH2CH2), 1.26 (s, 6H, 2×CH3), and 1.28 (s, 6H, 2×CH3).

Provenance & Evidence