Synthesis organic photochemistry: photochemical approach to hydroazulenes by photolysis of a βγ-unsaturated ketones

Abstract

Direct irradiation of 2-methyl-2-(cyclopent-l-eny1)cyclopentanone (1) gives the hydroazulene (Z), whereas the tricyclic ketone (4) is produced upon sensitized irradiation in acetone.

Synthetic Aspects of the Di-π-methane Rearrangement

“…However, under the same conditions, trimethylsubstituted ketone 93 gives a mixture of products 94 Scheme 24 3074 Chemical Reviews, 1996, Vol. 96,No. 8 Zimmerman and Armesto + + and 95 resulting from a normal oxa-di-π-methane rearrangement and the vinylogous ODPM reaction, respectively.…”

“…87 This is in contrast to the results obtained for the cycloalkenyl ketones 72c-e in which the presence of the double bond in a six-, seven-, or eight-membered ring suppresses the ODPM rearrangement. 93 Still further examples of ODPM reactivity in cycloheptenone derivatives have been reported for ketones 82 96 and 83 97 although in these cases the flexibility of the double bond is much more restricted than in 81.…”

Synthesis and biological activity of cocaine analogs. 2. 6H-[2]Benzopyrano[4,3-c]pyridin-6-ones

“…2-(MethoxycarbonyI)-2-[2-(methoxycarbonyl)phenyl]acetic Acid (12). A solution of diisopropylamine (25.3 g, 253 mmol) in 250 mL of dry THF under an N2 atmosphere was cooled to between -10 and -15 °C in a dry ice-acetone bath, and 162 mL of 1.6 N n-butyllithium was added.…”

Acid-catalyzed ketone rearrangements. Synthesis of decalins and spiro[4,5]decanes

“…Acid-Catalyzed Rearrangement of 2-Methyl-2-(l-cyclopent-1 -yl)cyclopentanone (1). A solution of 1.0 g of ketone 1 in 25 ml of benzene (under Na) was brought to reflux and then 1.0 ml of freshly distilled boron trifluoride etherate was added via a syringe.…”