Meth3: DCC as dehydrate reagent, DMAP as catalyzer, acetic acid as acetylate reagent reacted with AP in anhydrous DMSO at 40? for 48h.

• 方法三：以DCC为脱水剂，冰醋酸为乙酰化试剂，DMAP为催化剂在40℃下反应48h。