Hydrochloric Acid → 12,13-Bis-(4-methoxyphenyl)tetrahydropyranyl pentadecan-1,12-diol

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Reaction Steps

4'-methoxy-2-ethyl,2-(4-methoxyphenyl) acetophenone 13 (710 mg, 2.5 mmol, prepared from desoxyanisoin, ethyl bromide and LDA by a known method) in THF (10 ml) are added, under argon, to Grignard reagent prepared from 11-bromo-tetrahydropyranyl undecanol (6.6 g, 19.7 mmoles) and magnesium (0.6 g, 24.7 mmoles) and THF (10 ml). The mixture was stirred for 18 hours, then acidified with 1N HCl and extracted three times with ether. The organic phase was washed with water (X3), dried over anhydrous magnesium sulfate, and evaporated under reduced pressure. The residue was chromatographed on Silica gel (Kieselgel, 60F254, Merck, 0.063-0.200 mm, 100 g). Elution with a mixture of hexane-ethyl acetate (9:1 v/v) gave 12,13-Bis-(4-methoxyphenyl)-tetrahydropyranyl pentadecan-1,12-diol (991 mg, 76%) as a mixture of diastereoisomers; colorless oil, IR νmax (neat) 3480, 1600 cm-1 ; 1H-NMR (δ, CDCl3); 0.62 (3H, t, J=7.3 Hz, CH2CH3), 2.73 (1H, 2d, J=9.7 Hz, --CHCH2CH3), 3.25-4.00 (4H, m, --CH2OCHOCH2 --), 3.76 and 3.79 (6H, 2s, --OCH3), 4.57 (1H, t, J=1.1 Hz, --O3 --CH--CH2) and 6.71-7.30 (8H, m,H-Ar)ppm. MS m/e=523 (M+ -H2O).

Provenance & Evidence