反应详情

(±)tert-butyl 7-formyl-8-azaspiro[4.5]decane-8-carboxylate (Intermediate 72, 2 g, 7.48 mmol) was dissolved in dichloroethane (25 ml), then acetic acid (5 eq) and 2-amino 6 picoline (810 mg, 7.48 mmol) were added. After 3 hours at room temperature NaBH(OAc)3 (2.53 g, 11.96 mmol) was added and the reaction was maintained under stirring at room temperature for 18 hours. The reaction was poured in aqueous NaHCO3 and extracted with ethylacetate. The organic layers were combined, dried (Na2SO4) and concentrated under vacuum; the crude was then purified by silica gel column chromatography (petroleum ether/ethyl acetate=9/1) to obtain 1.3 g of intermediate as colourless oil.

1. temperaturethe reaction was maintained
2. extractionextracted with ethylacetate
3. dry with materialdried (Na2SO4)
4. concentrationconcentrated under vacuum
5. customthe crude was then purified by silica gel column chromatography (petroleum ether/ethyl acetate=9/1)