Heterodiene cycloadditions: Preparation and transformations of some substituted pyrano[4,3-b][1]benzopyrans
作者:Simon J. Coutts、Timothy W. Wallace
DOI:10.1016/s0040-4020(01)85668-4
日期:1994.1
Heterodienecycloadditions of 4-oxo-4H-1-benzopyrans with formyl, acetyl, or carboxyl substituents at C-3 to 1-alkoxy- or 1,1-dialkoxyalkenes produce 3-alkoxy- or 3,3-dialkoxy-4,4a- dihydropyrano[4,3-b][1]benzopyran-10-ones which are capable of a variety of selective transformations, including acid-induced epimerisation and/or retro-cycloaddition, reduction, hydrolysis and alcoholysis, in some cases
4-氧代-4 H -1-苯并吡喃在C-3处具有甲酰基,乙酰基或羧基取代基的异二烯环加成反应会生成3-烷氧基-或3,3-二烷氧基-4, 4a-二氢吡喃并[4,3- b ] [1]苯并吡喃-10-酮,在某些情况下,能够在多种条件下进行多种选择性转化,包括酸诱导的差向异构和/或逆环加成,还原,水解和醇解非常温和的条件。
A route to functionalised 1,5-dicarbonyl systems via heterodiene cycloadditions of a 2-acyl-2-enoic acid
作者:Simon J. Coutts、Timothy W. Wallace
DOI:10.1016/s0040-4039(00)95627-2
日期:——
Chromone-3-carboxylic acid 1 undergoes heterodienecycloadditions to alkoxyalkenes 2, producing novel pyrans which on treatment with alkanols or water decompose into functionalised 1,5-dicarbonyl systems 6 – 11, the sequence being potentially general for 2-acyl-2-enoic acids.