例： CH2OH CH2OCH3 NaOH,H2O —0 OH OCH31 wwOCH3 (CH30)2S02 2 OCH OCH3 Ph3Cd HCI,H2O Py 100C,1hr CH2OCPh3 CH2OCH3 -0 OH OH OCH3 wOH OCH OCH3 Py CH2OCPh3 CH2OH H,EtOH -0 OAc OAc OAC OAc OAc Organic Chem Organic Chem 例： O OH OH OH CH2OH OH NaOH , H2O （CH3O）2SO2 O OCH3 OCH3 OCH3 CH2OCH3 OCH3 Ph3Cd Py HCl，H2O 100℃,1hr O OH OH OH CH2OCPh3 OH O OCH3 OCH3 OCH3 CH2OCH3 OH Ac2O Py O OAc OAc OAc CH2OCPh3 OAc H , EtOH O OAc OAc OAc CH2OH OAc