Photolysis of α-diazocyclopentanones. Ring contraction to functionalised cyclobutanes and synthesis of junionone, grandisol and planococcyl acetate
作者:Arun Ghosh、Ujjal K. Banerjee、R.V. Venkateswaran
DOI:10.1016/s0040-4020(01)88398-8
日期:1990.1
a known precursor of grandisol (1). The diazoketone 28, on photolysis yielded a mixture of cyclobutane carboxylates 29 and 30. Conversion of the trans acid 31 to a methyl ketone followed by oxidative functionalisation of the phenyl group gave the keto ester 36 which was isomerised under acid catalysis to 37, which in opticallyactive form had been a precursor to (-) grandisol. Photolysis of diazoketone
Farbstoffsensibilisierte Photo-Oxygenierung von 6,6-Dimethylfulven. Eine neue 1,2-Dioxolan-Umlagerung
作者:W. Skorianetz、K. H. SchulteW-Elte、G. Ohloff
DOI:10.1002/hlca.19710540720
日期:1971.11.1
The dye sensitized photo-oxygenation of 6,6-dimethylfulvene (1) in solution at 15° gives enol lactone 2, along with ketoles 3 and 4. The following mechanism is proposed: initially formed endoperoxide 11 undergoes a 1,2-dioxolan rearrangement to give allen epoxide 12, which then isomerizes to cyclopropanone 13. 13 can then cyclise to give 2 and 3.