Thermal and photochemical transformations of tetraphenyl-p-dioxadiene

Domino reaction sequences leading to the formation of 2:2 adducts between acenaphthenequinone and acetophenone

“…The mechanism of carbonyl-olefin cyclization is understood in terms of ketyl intermediates generated by single electron transfer to the carbonyl group. Single electron transfer mediated carbonyl-olefin cyclizations 19,20 and single electron transfer from nucleophiles 21 are well documented in the literature. We assume that the presence of a highly electron deficient molecule such as acenaphthenequinone under strongly basic conditions enables electron transfer reactions leading to eventual carbonyl-olefin cyclization indicated in Scheme 2.…”

A one step synthesis of 2, 2, 3, 4-tetraphenyl-3-buteno-4- lactone from benzoin

“…The mixture was carefully and cautiously diluted with water (200cm3 ). An orange--red precipitate was separated by filtration, washed thoroughly with water and recrystallised several times fram ethanolchloroform mixture (1:l) to give colourless plates (1.41g, 86%); mp 1 3 7 4. '~ (lite:137.1°~-137.60 C); mixed mp with benzoin (mp 137' C) depressed; elemental analysis, found C, 86.21; H, 5.03%; expected for C2 8H,002, C, 86.57; H, 5.19% NMR(CDC13) 7.8 -7.2 (m, ring protons); IR(KBr), 3020,1785,1635,1600,1590, 1280, 1210,1000,750,690 cm-' .…”