反应详情

Under nitrogen, at −30° C. slowly add BF3.□Et2O (1.7 g, 12 mmol) to a solution of (−)-B-chlorodiisopinocampheylborane (6.1 g, 19 mmol) in THF (40 mL). Cool the solution to −40° and add 2-(2-isopropoxy-3-methylphenyl)-1-(4-pyridinyl)ethanone (3.2 g, 12 mmol). Allow the solution to slowly come to room temperature and stir for 15 hr. Add MeOH and 3M aqueous HCl to the reaction mixture and stir for an additional 45 min. Evaporate the solvent and dissolve the residue in 3M aqueous HCl and wash with heptane. Neutralize the aqueous fraction with 50% aqueous NaOH to pH 12 and extract with EtOAc. Wash the organic phase was with brine and dry over MgSO4. Evaporate the solvent to afford a yellow oil. Purify the oil by chromatography over SiO2 using EtOAc:heptane (1:1). Evaporate the product-containing fraction to give (S)-2-(2-isopropoxy-3-methylphenyl)-1-(4-pyridinyl)ethanol as an oil, 1.16 g (36%); 1H-NMR (CDCl3) δ 8.5-6.8 (m, 7H), 4.9 (m, 1H), 4.3 (m, 1H), 3.1-2.9 (m, 2H), 2.3 (s, 3H), 1.3 (d, 6H).

1. customat −30° C.
2. temperatureCool the solution to −40°
3. customto slowly come to room temperature
4. customEvaporate the solvent
5. dissolutiondissolve the residue in 3M aqueous HCl
6. washwash with heptane
7. extractionNeutralize the aqueous fraction with 50% aqueous NaOH to pH 12 and extract with EtOAc
8. washWash the organic phase
9. dry with materialdry over MgSO4
10. customEvaporate the solvent
11. customto afford a yellow oil
12. customPurify the oil by chromatography over SiO2
13. customEvaporate the product-containing fraction