Computational Chemistry and Molecular Modeling
Atomic, Molecular and Optical Physics
Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
Ketene cycloadditions give predominantly the more hindered product. This has been adduced as evidence for concerted antarafacial cycloaddition in accord with the Woodward-Hoffmann rules. However, stepwise mechanisms, heretofore discounted, are now shown to account for the products in a simple least-motion manner that requires only that rotation in the intermediates be not greatly faster than cyclization. This requirement is amply supported by the literature. © 1994 John Wiley & Sons, Inc.
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