Intramolecular Base-Free Catalytic Wittig Reaction: Synthesis of Benzoxepinones

Journal of Organic Chemistry 2019
A. Grandane, L. Longwitz, C. Roolf, A. Spannenberg, H.M. Escobar, C. Junghanss, Edgars Sūna, T. Werner

A straightforward two-step synthesis of benzoxepinones was developed via base-free phosphane-catalyzed Wittig reaction. 3-Methyl-1-phenyl-2-phospholene 1-oxide was used as a precatalyst and trimethoxysilane as a reducing agent. Additionally benzoic acid is employed as a catalyst to facilitate the reduction of the phosphane oxide. Mechanistic investigation revealed the formation of a coumarin as a side product, which was identified by 2D NMR experiments. First results of metabolic activity tests on the prepared benzoxepinones are reported.

DOI
10.1021/acs.joc.8b02789
Hyperlink
https://pubs.acs.org/doi/10.1021/acs.joc.8b02789

Grandane, A., Longwitz, L., Roolf, C., Spannenberg, A., Escobar, H., Junghanss, C., Sūna, E., Werner, T. Intramolecular Base-Free Catalytic Wittig Reaction: Synthesis of Benzoxepinones. Journal of Organic Chemistry, 2019, Vol. 84, No. 3, pp.1320-1329. ISSN 0022-3263. Available from: doi:10.1021/acs.joc.8b02789

Publication language
English (en)