Aryl- and cyclopropyl-substituted allene enynes were prepared by a double olefination procedure from various aldehydes, and their cycloaromatization reactions were subjected to kinetics measurements in methanol and 1,4-cyclohexadiene solvents. The results support previous proposals of a polar diradical transition state for the cycloaromatization process. (C) 1998 Elsevier Science Ltd. All rights reserved.