反应详情

A solution of 13.8 g (34.5 mmol) of (-)-1,2-di-p-toluene-sulfonyl glycerol (see Formula (I) in Scheme 2) in 100 ml of dry methylenechloride is added to 100 ml of liquid isobutylene taken in a pressure bottle at -78° C. Concentrated sulfuric acid (0.2 ml) is added to the above reaction mixture, the contents are stirred, and the mixture is then allowed to warm to room temperature and stirred for 16 hours. The pressure is gradually released, and the solution is neutralized with aqueous sodium bicarbonate solution. The organic layer is separated, washed with water, and dried over Na2SO4. The solvent is removed on a rotary evaporator and the crude product is dried under reduced pressure. Recrystallization from absolute ethanol affords white crystals of (+)-t-butyl-2,3-di-p-toluenesulfonyl glycerol (see Formula (J) in Scheme 2), m.p. 70°-71° C. [α]D2 +3.44 (c, 5.9, CHCl3). 1H NMR (CDCl3)δ7.8 (m, 4H); 7.3 (m, 4H); 4.5 (m, 1H); 4.15 (d, 2H); 3.35 (d, 2H); 2.45 (s, 6H); 1.1 (s, 9H).

1. customtaken in a pressure bottle at -78° C
2. stirringstirred for 16 hours
3. customThe organic layer is separated
4. washwashed with water
5. dry with materialdried over Na2SO4
6. customThe solvent is removed on a rotary evaporator
7. dry with materialthe crude product is dried under reduced pressure
8. customRecrystallization from absolute ethanol