Mechanistic and synthetic aspects of the acid-catalysed hydrolysis of 2,2-dimethoxy-3,4-dihydropyrans into 3,4-dihydro-α-pyrones and δ-keto esters
作者:J.W. Scheeren、C.G. Bakker、R. Peperzak、R.J.F. Nivard
DOI:10.1016/s0040-4039(00)95431-5
日期:1987.1
Acid-catalysed hydrolysis of 2,2-dimethoxy-3,4-dihydropyrans () yields mixtures of δ-keto esters () and 3,4-dihydro-α-pyrones (). The amount of increases with increasing alkyl substitution in the 3-, 5- and 6-position of and when the hydrolysis is carried out in a two-phases system of water/dichloromethane. It is shown that is formed directly from whereas is formed directly from and by methanolysis
酸催化的2,2-二甲氧基-3,4-二氢吡喃()水解生成δ-酮酸酯()和3,4-二氢-α-吡喃酮()的混合物。当在水/二氯甲烷的两相系统中进行水解时,随着在3位,5位和6位烷基的取代增加而增加的量。结果表明,甲醇直接由形成,而甲醇则由甲醇直接形成。讨论了这些水解反应的机理和合成方面。