Domino Self-Sensitized Photooxygenation of Conjugated Dienones for the Synthesis of 1,2,4-Trioxanes

MISCHNE, MIRTA P.; MARTIREN, NADIA L.; RIVEIRA, MARTÍN J.

JOURNAL OF ORGANIC CHEMISTRY

AMER CHEMICAL SOC

Año: 2019 vol. 84 p. 3671 - 3677

0022-3263

The photochemical behavior of several dienones was studied under aerobic conditions. 2-Allylidene-1,3-cycloalkanediones prepared via Knoevenagel-type condensation between simple readily available 1,3-dicarbonyl substrates and α,β-unsaturated aldehydes afforded 1,2,4-trioxane derivatives upon UVA irradiation in the presence of oxygen. This domino self-sensitized photooxygenation cascade of conjugated carbonyl systems proceeds stereoselectively and involves the formation of two new oxa-cycles, three new bonds (two C-O), and three stereocenters.