反应详情

To a solution of oxalyl chloride (2.4 mL) in methylene chloride (75 mL) at −78° C. was slowly added dimethylsulfoxide (3 mL) in methylene chloride (25 mL). After 10 minutes, a solution of tert-butyl(2R,5R)-5-{[tert-butyl(dimethyl)silyl]oxy}-2-(hydroxymethyl)piperidine-1-carboxylate (Intermediate 190, 7.60 g) in methylene chloride (40 mL) was slowly added. After 30 minutes at −78° C., diisopropylethylamine (10 mL) was added and the reaction warmed to room temperature. The reaction was diluted with ethyl acetate, washed with 0.5 M HCl, NaHCO3 and brine solutions, dried (Na2SO4), filtered and concentrated. Chromatography on silica gel with a gradient of 0-30% ethyl acetate in hexanes gave 6.84 g of product.

1. customat −78° C.
2. waitAfter 30 minutes at −78° C.
3. washwashed with 0.5 M HCl, NaHCO3 and brine solutions
4. dry with materialdried (Na2SO4)
5. filtrationfiltered
6. concentrationconcentrated