反应详情

A solution of 3.17 g (8.78 mmol) of rac-3,4-Dihydro-5-hydroxy-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanol in 60 mL of anhy. DMF (Aldrich) was added to a suspension of 383 mg (1 eq) of sodium hydride (Aldrich) in 20 mL of anhy. DMF (Aldrich) and the mixture stirred at RT under argon for 0.5 hr. 2.28 mL (1 eq.) of tert-butylchlorodiphenylsilane (Aldrich) was then added by syringe. After stirring for 2 hr at RT the reaction was diluted with EtOAc, washed with 0.1N aq. HCl, water, sat. aq. NaCl, dried and evaporated under reduced pressure. The residue was purified by flash chromatography on silica gel, eluting with 30% EtOAc-hexane. The fractions containing the product were combined and evaporated under reduced pressure to give 2.23 g (45%) of 5-[[(1,1-Dimethylethyl)diphenylsilyl]oxy]-3,4-dihydro-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanol as a pale yellow oil. HR EI MS: Calc M+, 558.3530; Observed, 558.3516.

1. washwashed with 0.1N aq. HCl, water, sat. aq. NaCl
2. customdried
3. customevaporated under reduced pressure
4. customThe residue was purified by flash chromatography on silica gel
5. washeluting with 30% EtOAc-hexane
6. additionThe fractions containing the product
7. customevaporated under reduced pressure