反应详情

Crude [R-(R*,R*)]-1,1-dimethylethyl 6-cyano-3,5-dihydroxyhexanoate (about 150 moles) from Step (2) is diluted with 100 kg of 2,2-dimethoxypropane and acidified with about 1 L of methanesulfonic acid. The reaction is quenched by the addition of aqueous sodium bicarbonate solution and concentrated by vacuum distillation. The residue is diluted with 150 L of hexane, and the layers separated. The organic layer is washed with aqueous sodium bicarbonate solution and cooled to 0° C.±10° C. to crystallize. The product is collected by filtration and washed with cooled hexane, then dried affording 28.5 kg of (4R cis) 1,1-dimethylethyl 6-cyanomethyl-2,2-dimethyl-1,3-dioxane-4-acetate.

1. customThe reaction is quenched by the addition of aqueous sodium bicarbonate solution
2. concentrationconcentrated by vacuum distillation
3. additionThe residue is diluted with 150 L of hexane
4. customthe layers separated
5. washThe organic layer is washed with aqueous sodium bicarbonate solution
6. temperaturecooled to 0° C.±10° C.
7. customto crystallize
8. filtrationThe product is collected by filtration
9. washwashed with cooled hexane
10. customdried