2)单分子亲核取代反应(S、1)机理及其立体化学 CH3 CH3 CH3-C-Br +OH CH3COCH3 H20 CH3-C-OH Br CH3 ki[(CH3)3CBr] CH3 slow CH3 (1) CH3-C-Br CH3-C+ Br CH3 CH3 CH3 CH3 (2) C C+ CH3 +0 fast CH3-C-OH CH3CH3 C CH3 Br + OH - CH3 CH3 COCH3 H2 O CH3 C CH3 OH + Br - CH3 = k1[(CH3)3CBr] 2) 单分子亲核取代反应(SN1)机理及其立体化学 CH3 C CH3 Br CH3 CH3 C CH3 CH3 + + Br - CH3 C CH3 CH3 + + OH - CH3 C CH3 OH CH3 （1） （2） slow fast