The intramolecular enyne diels-alder reaction. Stereoselective construction of tricyclic dioxadienones and mechanistic outline
摘要:
4-Methylpent-4-en-2-yn-1-ols and 6-hydroxy-2,3-dihydro-6H pyran 3-ones are condensed in different ways to a series of tricyclic dioxadienones which contain the basic framework of the cadlinolides. A mechanism of the intramolecular enyne-ene cycloisomerization and the origin of the resulting type I and type II dienes is proposed.
Synthesis of benzofurans via an acid catalysed transacetalisation/Fries-type O → C rearrangement/Michael addition/ring-opening aromatisation cascade of β-pyrones
作者:Siddheshwar K. Bankar、Jopaul Mathew、S. S. V. Ramasastry
DOI:10.1039/c6cc01016d
日期:——
An unusual and facile approach for the synthesis of 2-benzofuranyl-3-hydroxyacetones from 6-acetoxy-[small beta]-pyrones and phenols is presented.
提出了一种由6-乙酰氧基-β-吡喃酮和苯酚合成2-苯并呋喃基-3-羟基丙酮的不寻常且简便的方法。
The intramolecular enyne diels-alder reaction. Stereoselective construction of tricyclic dioxadienones and mechanistic outline
4-Methylpent-4-en-2-yn-1-ols and 6-hydroxy-2,3-dihydro-6H pyran 3-ones are condensed in different ways to a series of tricyclic dioxadienones which contain the basic framework of the cadlinolides. A mechanism of the intramolecular enyne-ene cycloisomerization and the origin of the resulting type I and type II dienes is proposed.
De Novo Asymmetric Bio- and Chemocatalytic Synthesis of Saccharides − Stereoselective Formal <i>O</i>-Glycoside Bond Formation Using Palladium Catalysis
作者:Alex C. Comely、Rienk Eelkema、Adriaan J. Minnaard、Ben L. Feringa
DOI:10.1021/ja0347538
日期:2003.7.1
approach to the de novo catalytic asymmetric synthesis of saccharides has been developed. Acetoxypyranones obtained enantiopure by enzymatic resolution have been shown to undergo highly stereoselective palladium-catalyzed formal O-glycoside bond formation. The combination of these protocols can be applied to the iterative asymmetric catalytic synthesis of saccharides.