5.由醇氧化或脱氢 H,0,GH,0,0HGD7→CH,CH,0H,0H02%(随时蒸出 H2S04 醛 CH,CH2-○0HNa2Cr20 →CH3CH2○>090% H2S04 酮 CH1CH2O Cr0吡啶 CHCl225℃ n-CHIsCHO 95 OH Cu0 0 250-3009C 92别