Metal-Free Brønsted Acid-Catalyzed Rearrangement of δ-Hydroxyalkynones to 2,3-Dihydro-4<i>H</i>-pyran-4-ones: Total Synthesis of Obolactone and a Catechol Pyran Isolated from <i>Plectranthus sylvestris</i>
作者:Sachin P. Gholap、Dashrath Jangid、Rodney A. Fernandes
DOI:10.1021/acs.joc.8b03141
日期:2019.3.15
A metal-free, Brønsted acid, pTsOH-catalyzed intramolecular rearrangement of δ-hydroxyalkynones to substituted 2,3-dihydro-4H-pyran-4-ones was developed. The rearrangement occurs with high regioselectivity under mild and open-air conditions. The scope of work was illustrated by synthesizing an array of aliphatic and aromatic substituted 2,3-dihydro-4H-pyran-4-ones in up to 96% yield, 100% atom economy
开发了一种无金属,布朗斯台德酸,p TsOH催化的δ-羟基炔烃分子内重排成取代的2,3-二氢-4 H-吡喃-4-酮。在温和的露天条件下,重排发生时具有很高的区域选择性。通过合成一系列脂族和芳族取代的2,3-二氢-4 H-吡喃-4-酮以高达96%的收率,100%的原子经济性和完全的区域选择性来说明工作范围。某些二氢吡喃酮用于乙烯基卤代反应,以完成生物活性天然产物,己内酯和从香叶忍冬属植物(唇形科)中分离出的邻苯二酚吡喃的全合成。