反应详情

To an ice-cooled solution of 384 Mg (2 mmol) of 4-acetoxy-trans-cinnamylalcohol (I) in 18 ml of anhydrous methylene chloride is added 1.2 ml of 3.32N-cumene hydroperoxide/methylene chloride solution under nitrogen atmosphere and the reaction mixture stirred under ice-cooling. 0.402N Solution (0.666 ml) of titanium tetraisopropoxide in methylene chloride is mixed with 0.407N solution (0.98 ml) of diethyl-L-(+)-tartrate in methylene chloride under nitrogen atmosphere, and the mixture allowed to stand for one hour and then added to the above reaction mixture in three portions every 10 minutes. After 45 minutes, the mixture is poured into a saturated aqueous solution of sodium fluoride (2.5 g) with vigorous stirring at room temperature for 15 minutes. Sodium chloride (16 g) is added and the mixture stirred for further 15 minutes. The precipitated gelatinous material is collected by filtration through a filter aid and washed with methylene chloride. The organic layer is dried over anhydrous magnesium sulfate and concentrated in vacuo. 1.24 g Oily residue is dissolved in carbon tetrachloride and filtered. The filtrate is concentrated in vacuo and a residue is dissolved in 5 ml of benzene, chromatographed on silica gel (Lobor B; made by Merck) and eluted with ethyl acetate/hexane (1:1) (each fraction 11 ml). Fractions which show a single spot in thin layer chromatography are collected and concentrated in vacuo to give 309 mg (74.3%) of the above-defined compound (II) as crystalline, mp. 59°-61° C., [α]D23 : -23.7±0.6° (c 1.017, chloroform).

1. temperaturecooling
2. additionadded to the above reaction mixture in three portions every 10 minutes
3. waitAfter 45 minutes
4. stirringwith vigorous stirring at room temperature for 15 minutes
5. stirringthe mixture stirred for further 15 minutes
6. filtrationThe precipitated gelatinous material is collected by filtration through a filter aid
7. washwashed with methylene chloride
8. dry with materialThe organic layer is dried over anhydrous magnesium sulfate
9. concentrationconcentrated in vacuo
10. dissolution1.24 g Oily residue is dissolved in carbon tetrachloride
11. filtrationfiltered
12. concentrationThe filtrate is concentrated in vacuo
13. dissolutiona residue is dissolved in 5 ml of benzene
14. customchromatographed on silica gel (Lobor B; made by Merck)
15. washeluted with ethyl acetate/hexane (1:1) (each fraction 11 ml)
16. customare collected
17. concentrationconcentrated in vacuo