反应条件
1: oxalyl chloride / CH2Cl2; dimethylformamide / 1 h / 0 °C 2: CH2Cl2 / 1 h / Ambient temperature 3: 93 percent / TFA / 10 - 15 °C 4: 1.) 4-formyl-1-methylpyridinium benzenesulfonate, 2.) DBU, 3.) aq. oxalic acid / 1) CH2Cl2, DMF, room temperature; 2) 5 min; 3) cooling, 0.5 - 1 h 5: 1.) Jones reagent, 2.) aq. HCl / 1) room temperature, acetone; 2) heating View Scheme
参考文献
Journal of the American Chemical Society, , vol. 104, # 16 p. 4446 - 4450
