Etude des petits cycles—XXXVI. Photo-oxygenation d'alkylidenecyclopropanes. Syntheses specifiques d'alkenylcyclopropanols, de β′-hydroxy α-enones et d'α,α′-dienones
作者:G. Rousseau、P. le Perchec、J.M. Conia
DOI:10.1016/0040-4020(76)88022-2
日期:1976.1
The dye-sensitizedphoto-oxygenation of alkylidenecyclopropanes 1a–4a at –50°C gives the hydroperoxydes 1b–4b, which were reduced in situ by PPh3 into 1-alkenylcyclopropanols 1c–4c in high yield. At higher temperatures, 1b–4b rearranged exclusively into β′-hydroxy α-enones 1d–4d if pyridine was added (α,α′-dienones 1e–4e are also formed competitively in absence of pyridine). At 3°C the photosensitised