Water → HCID 90085834, compound

Participants

Reaction Steps

Ethyl (2E)-5-[8-hydroxy-2,3,7,9-tetramethyl-9-(trifluormethyl)-1,4-dioxaspiro[4.5]dec-6-en-8-yl]-3-(trifluoromethyl)pent-2-en-4-ynoate (110 mg, 0.23 mmol) was dissolved in acetone (5 ml) under argon in a round-bottom flask, and 5 drops of conc. hydrochloric acid were added. The resulting reaction solution was stirred at room temperature for 4 h and then water was added. After removing acetone under reduced pressure, the aqueous phase was extracted repeatedly with dichloromethane. The combined organic phases were dried over magnesium sulfate, filtered and concentrated under reduced pressure. By column chromatography purification of the resulting crude product (ethyl acetate/heptane gradient), ethyl (2E)-5-[1-hydroxy-2,6-dimethyl-4-oxo-6-(trifluoromethyl)cyclohex-2-en-1-yl]-3-(trifluoromethyl)pent-2-en-4-ynoate (70 mg, 71% of theory) was isolated in the form of a colorless viscous oil. 1H-NMR (400 MHz, CDCl3 δ, ppm) 6.72/6.71 (s, 1H), 5.98/5.97 (s, 1H), 4.28/3.93 (q, 2H), 3.28 (br. s, 1H, OH), 3.00 (d, 1H), 2.66 (d, 1H), 2.21/2.18 (s, 3H), 1.49/1.37 (s, 3H), 1.32/1.09 (t, 3H).

Provenance & Evidence