Direct observation of .alpha.-oxo ketenes formed from 1,3-dioxin-4-ones and the enols of .beta.-keto esters
作者:Beat Freiermuth、Curt Wentrup
DOI:10.1021/jo00007a008
日期:1991.3
The enol forms of beta-keto esters thermolyze to alcohols and alpha-oxo ketenes, which are characterized by low-temperature IR spectroscopy and on warming regenerate the beta-hydroxy-alpha,beta-unsaturated esters. The matrix isolated s-Z and s-E forms of alpha-oxo ketenes are characterized and photochemically converted into other conformers or sites. Matrix photolysis of 2,2,6-trimethyl-1,3-dioxin-4-one gives the s-Z acetylketene initially. Alpha-Oxo ketenes polymerize in the cold and dimerize only at elevated temperatures.