Water → 6,7-Dimethyl-4-oxo-1,2,3,4-tetrahydrophenanthrene

Participants

Reaction Conditions

Reaction Steps

t-BuOK (3.6 g, 0.032 mole) was dissolved in 250 ml of dry benzene at 40°-50° C. To the stirred solution was added 6,7-Dimethyl-4-oxo-1,2,3,4-tetrahydrophenanthrene (3.6 g, 0.016 mole) in 50 ml of dry benzene and then, 10-undecenyl iodide (4.58 g, 0.016 mole) at 30° C. under N2. The mixture was heated to 60° C. for 2.5 hr under N2. After cooling the reaction mixture to room temperature, water was added. The whole mixture was extracted twice with diethylether. The combined diethylether solution was dried over anhydrous MgSO4 and then concentrated. Flash column chromatography of the residue on silica gel afforded 6,7-Dimethyl-4-oxo-3-(10-undecenyl)-1,2,3,4-tetrahydrophenanthrene as a sticky brown solid (2.36 g, 0.0063 mole, 39% yield) as a desired product, and unreacted 6,7-Dimethyl-4-oxo-1,2,3,4-tetrahydrophenanthrene (1.70 g, 47% recovered). 1H NMR (CDCl3)δ 1.29-1.62 (m,14H), 1.86-2.08 (m,4H), 2.21-2.35 (m,2H), 2.40 (s,3H), 2.46 (s,3H), 2.52-2.63 (m,1H), 3.07-3.13 (m,2H), 4.90-5.04 (m,2H), 5.75-5.89 (m,1H), 7.17 (d, J=8.2 Hz,1H), 7.53 (s,1H), 7.77 (d, J=8.2 Hz,1H), 9.10 (s,1H), IR (KBr) cm-1 2920, 2850, 1669, 1600, exact (EI) mass. calcd. for C27H36O: 376.2766, Found: 376.2766.

Provenance & Evidence