Methacryloyl chloride dimers: from structure elucidation to a manifold of chemical transformations
作者:Jonas Warneke、Ziyan Wang、Matthias Zeller、Dieter Leibfritz、Markus Plaumann、Vladimir A. Azov
DOI:10.1016/j.tet.2014.07.019
日期:2014.9
We report the isolation and elucidation of structure, formation mechanisms, and reactivity of elusive methacryloyl chloride dimers. Upon standing of a sample of methacryloyl chloride (1) for prolonged periods of time dimer 3 forms via oxa-Diels-Alder reaction even at low temperatures. If traces of a Lewis acid are present, dimer 3 isomerizes into a mixture of 2-oxo-cyclopentanecarbonyl chlorides 4, 14, and traces of 5, with a relative ratio that depends on the nature of the Lewis acid and reaction time. Dimer 3 can also be separated and isolated by vacuum distillation and selectively converted into derivatives of 2,5-dimethyl-2-hydroxyadipic acid, as well as into the compound 14 by treating with a catalytic amount of titanium tetrachloride. Additionally, based on the study, suggestions on purification and handling of methacryloyl chloride are proposed. (C) 2014 Elsevier Ltd. All rights reserved.