反应详情

A solution of 1,1-dimethylethyl 4-(4-hydroxy-1-butyn-1-yl)benzoate (0.9 g, e.g. which can be as prepared in Intermediate 22) in a mixture of ethanol (50 ml) and ethyl acetate (5 ml) was hydrogenated over platinum(IV) oxide (PtO2, 0.09 g, 10% w/w) for 18 hours at room temperature. The mixture was filtered through a bed of Celite, washing through with ethanol. The solvents were evaporated to dryness to give the title compound as a yellowy/brown oil (0.85 g). 1H NMR (400 MHz, chloroform-d) δ (delta) ppm 1.60 (14H, m), 1.70 (2H, m), 2.70 (2H, t, J=7.53 Hz & 7.78 Hz), 3.67 (2H, t, J=6.53 Hz & 6.27 Hz) 7.23 (2H, d, J=8.28 Hz), 7.91 (2H, d, J=8.03 Hz). Extra protons at about 1.5-1.6 ppm may perhaps be due to residual H2O in CDCl3. LCMS showed TRET=3.26 min with: MH+ not seen, and [MH]++18 adduct=268.

1. filtrationThe mixture was filtered through a bed of Celite
2. washwashing through with ethanol
3. customThe solvents were evaporated to dryness