反应详情

To (S)-tert-butyl 5-(hydroxymethyl)-6-azaspiro[2.5]octane-6-carboxylate (Intermediate 18, 20 g, 82.0 mmol) dissolved in 80 ml of DCM, TEMPO (2.6 g, 16 mmol) and BAIB (29.3 g, 90 mmol) were added. After 2 hours at 25° C., the reaction is diluted with DCM (150 ml), washed with an aqueous solution of Na2S2O3 then with water, dried (Na2SO4) and evaporated to obtain a crude that was purified by silica gel chromatography (petroleum ether to petroleum ether/ethylacetate 95/5). (S) tert-butyl 5-formyl-6-azaspiro[2.5]octane-6-carboxylate was obtained as light yellow solid (7 g).

1. washwashed with an aqueous solution of Na2S2O3
2. dry with materialwith water, dried (Na2SO4)
3. customevaporated
4. customto obtain a crude that
5. customwas purified by silica gel chromatography (petroleum ether to petroleum ether/ethylacetate 95/5)