A fragmentation-photocyclization approach towards homosecohexaprismane skeleton

Recent Advances in the Synthesis of Cyclobutanes by Olefin [2 + 2] Photocycloaddition Reactions

“…performed the sensitized (acetone as solvent) intramolecular [2 + 2] photocycloaddition reaction of a cyclic 1,2-dichloroalkene to another cyclohexene in high yields. 136 Tetrathiatetraasterane ( 58 ) represents another aesthetically appealing compound, which was prepared by [2 + 2] photocycloaddition. 137 Precursor 57 , which was available by [2 + 2] photodimerization, 138 has a long wavelength absorption due to conjugation of the sulfur with the olefinic double bond.…”

“…In work related to birdcaged hydrocarbons, Chou et al. performed the sensitized (acetone as solvent) intramolecular [2 + 2] photocycloaddition reaction of a cyclic 1,2-dichloroalkene to another cyclohexene in high yields . Tetrathiatetraasterane ( 58 ) represents another aesthetically appealing compound, which was prepared by [2 + 2] photocycloaddition .…”

Intramolecular [2 + 2] Photocycloaddition of Alkenes Incorporated in a Carbohydrate Template. Synthesis of Enantiopure Bicyclo[3.2.0]heptanes and -[6.3.0]undecanes

“…In general, the [2 + 2] photocycloaddition of an alkene to a conjugated system such as an enone or a diene can be achieved either on direct irradiation or irradiation in the presence of a photosensitizer. On the other hand, photoaddition of an alkene to a nonconjugated alkene is possible only in the presence of metal catalyst, except in few examples where the reacting alkenes are either strained or closely held in conformationally rigid molecules. The bis(copper(I)trifluoromethane sulfonate)−benzene complex [(CuSO 3 CF 3 ) 2 ·C 6 H 6 ](CuOTf) introduced by Salomon and Kochi has been found to be the most efficient catalyst for accomplishing both inter- and intramolecular additions.…”