Potassium Hydroxide → (2E)-3-{4-[(4-Hydroxyphenyl)(2,2,6,6-tetramethyltetrahydro-4H-pyran-4-ylidene)methyl]phenyl}prop-2-enoic acid

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Reaction Conditions

Reaction Steps

Ethyl (2E)-3-{4-[(4-hydroxyphenyl)(2,2,6,6-tetramethyltetrahydro-4H-pyran-4-ylidene)methyl]phenyl}prop-2-enoate (54) (0.1095 g, 0.260 mmole) was dissolved in ethanol (5 mL). Potassium hydroxide (0.260 mL of a 3 M aqueous solution, 0.780 mmole) was added and the mixture was heated to 75° C. for 2.5 h. The solution was cooled to RT and concentrated. Water (25 mL) was added and the mixture was extracted with ether (10 mL). The organics were thrown out and the aqueous layer was treated with 1 N aqueous HCl to pH=3. The resulting mixture was extracted with methylene chloride (3×10 mL). The organics were dried (Na2SO4) and concentrated to provide 0.097 g (95%) of compound 55 as a pale yellow solid. 1H NMR (DMSO-d6): δ 12.33 (s, 1H), 9.34 (s, 1H), 7.59 (d, J=8.2 Hz, 2H), 7.52 (d, J=15.9 Hz, 1H), 7.15 (d, J=8.2 Hz, 2H), 6.93 (d, J=8.4 Hz, 2H), 6.67 (d, J=8.4 Hz, 2H), 6.44 (d, J=15.9 Hz, 1H), 2.14 (s, 2H), 2.11 (s, 2H), 1.11 (s, 6H), 1.10 (s, 6H). LRMS (ESI): m/z 391 (M−H)−.

Provenance & Evidence