反应详情

A solution of 9.4 g of 5-Pentyl-2-[1-(tetrahydro-2,2-dimethyl-2H-pyran-3-yl)ethyl]-1,3-benzenediol in 400 mL of toluene containing a catalytic amount of pyridinium para-toluenesulfonic acid (Aldrich) was heated to 60° C. under argon for 2 hr. The reaction was cooled to RT, diluted with EtOAc, washed with 0.1N aq. HCl (×2), water (×2), sat. aq. NaHCO3, dried and evaporated under reduced pressure. The material obtained was purified by extensive chromatography to give 3.4 g (35%) of rac-3,4-Dihydro-5-hydroxy-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanol as a pale yellow amorphous solid. HR EI MS: Calc M+, 320.2351; Observed, 320.2377. Ratio of 3:1 diastereoisomers as shown by 1 H-NMR.

1. washwashed with 0.1N aq. HCl (×2), water (×2), sat. aq. NaHCO3
2. customdried
3. customevaporated under reduced pressure
4. customThe material obtained
5. customwas purified by extensive chromatography