Synthesis and structural studies of 5,7(4,6)-di(tert-butyl)-2-(6,8-dimethyl-4-chloroquinolin-2-yl)-1,3-tropolones by quantum-chemical methods and two-dimensional correlation NMR spectroscopy

摘要

4,6-Di(tert-butyl)-2-(quinolin-2-yl)-1,3-tropolone (7') was isolated for the first time from the acid-catalyzed reaction of 2-methyl-substituted nitrogen heterocycles with 1,2-benzoquinones, which proceeds with the expansion of the o-quinone ring to give mainly isomeric 5,7-di(tert-butyl)-2-(quinolin-2-yl)-1,3-tropolone.