Inter??and Intramolecular Hetero Diels??Alder Reactions, Part XXVI. Diastereoselectivity and Kinetics of Intermolecular Hetero Diels??Alder Reactions under High …
Abstract The Hetero Diels-Alder reaction of the enamino ketones 5a–d and ethyl vinyl ether (2) to give the dihydropyrans 6a–d and 7a–d is studied in dichloromethane and in heptane/isodurene under high pressure up to 7 kbar at temperatures between 0.5 and 130 C. The kinetics is measured by on-line FT-IR spectroscopy. The cycloaddition shows a remarkable pressure-dependent increase of diastereoselectivity in favour of the cis ...
