CHEMISTRY OF ALPHA,BETA-UNSATURATED THIONE DIMERS .2. REACTIONS OF THIOCHALCONES AND 2-ARYLIDENE-1-THIOTETRALONES WITH SOME OLEFINS AND THE PARENT KETONES OF THE THIONES

Thiochalcone, 4'-methoxythiochalcone, 2-benzylidene- 1-thiotetralone, 2-(p-methoxybenzylidene)-l-thiotetralone, and 2-(p-chlorobenzylidene)-l-thiotetralone formed by the retro-Diels-Alder reaction of the corresponding dimers reacted with maleic anhydride, citraconic anhydride, styrene, n-butyl vinyl ether, norbornene, and norbomadiene to give the [4 + 2] cycloadducts, respectively. Theseα, β-unsaturated thiones also reacted as a diene with the parent ketones to afford the cycloadducts. Simple qualitative consideration by frontier molecular orbital theory has been made on these cycloaddition reactions. Copyright © 1979, American Chemical Society. All rights reserved.