Dipent-4-enyl acetals, which are congeniently prepared by treating ketones or aldehydes with pen-4-enyl alcohol under standard conditions, readily acetalize diols in acetonitrtile solvent, and although neutral promoters such as N-halogenosuccinimides and iodonium dicollidine peerchlorate are effective, the rates and yields are greatly enhanced by the addition of catalytic amounts of an acid.
4-
戊烯基
缩醛,通过在标准条件下用4-
戊烯醇处理酮或醛而天然制备,在
乙腈溶剂中容易
缩醛化二醇,尽管中性
促进剂如N-卤代琥珀
酰亚胺和
碘鎓二
可力丁高氯酸盐有效,但加入少量酸作为催化剂可以显著提高反应速率和产率。