Brønsted Acid-Catalyzed Cycloisomerization of But-2-yne-1,4-diols with or without 1,3-Dicarbonyl Compounds to Tri- and Tetrasubstituted Furans
作者:Srinivasa Reddy Mothe、Sherman Jun Liang Lauw、Prasath Kothandaraman、Philip Wai Hong Chan
DOI:10.1021/jo301093f
日期:2012.8.17
efficiently from cycloisomerization of but-2-yne-1,4-diols with or without 1,3-dicarbonyl compounds is described. By taking advantage of the orthogonal modes of reactivity of the alcoholic substrate through slight modification of the reaction conditions, a divergence in product selectivity was observed. At room temperature, p-TsOH·H2O-mediated tandem alkylation/cycloisomerization of the propargylic
描述了一种布朗斯台德酸催化的方法,该方法通过有或没有1,3-二羰基化合物的丁-2-炔基-1,4-二醇的环异构化反应有效地制备三和四取代的呋喃。通过稍微改变反应条件,利用醇类底物的正交反应模式,观察到产物选择性的差异。在室温下,p -TsOH·H 2炔丙基-1,4-二醇与β二羰基化合物的O-介导的串联烷基化/烷基环异构发现选择性发生,以提供四取代的呋喃产物。另一方面,发现将反应温度升高至80℃会导致优先的p -TsOH·H 2。O催化不饱和醇的脱水重排,并形成2,3,5-三取代的呋喃加合物。