84694-72-4Relevant academic research and scientific papers
Photochemistry of 1,5-hexadien-3-ones: Wavelength-dependent selectivity in intramolecular enone-olefin photoadditions
Dauben, William G.,Cogen, Jeffrey M.,Ganzer, George A.,Behar, Victor
, p. 5817 - 5824 (2007/10/02)
The photochemistry of ten 1,5-hexadien-3-ones in methanol is studied over the wavelength range of 313-366 nm, by using monochromatic light. With the goal of understanding the unusual wavelength-dependent selectivity observed for 5-methyl-1,5-hexadien-3-one (1), quantum yield measurements, structure reactivity studies, triplet sensitization, and quenching experiments are performed. While six of the ten dienones studied show selectivities that are independent of irradiation wavelength from 313 to 366 nm, four of the dienones exhibit wavelength-dependent selectivities that are similar to that observed in 1, thus establishing that 1 is not unique, as previously believed. Triplet sensitization studies suggest that the wavelength dependence results, largely, from a single-state α-cleavage reaction that competes with triplet cycloaddition. A variety of triplet quenchers were ineffective at inhibiting these reactions. Some possible mechanisms are discussed.
General Syntheses of 6- and 7-Carbomethoxy-trans-1-heteradecalins and 6- and 7-Carbomethoxy-trans-2-heteradecalins
Hirsch, Jerry A.,Truc, Vu Chi
, p. 2218 - 2227 (2007/10/02)
Two routes to all of the title compounds in the oxa and aza series have been studied.The most general path, involving a cyclohexene oxide intermediate, was not successful becauase of difficulty in separating regioisomers.Allylation of 4-carbomethoxycyclohexanone (11) followed by reduction produced the required trans-disubstituted allyl alcohols, which were converted to all of the desired 6-carbomethoxy-trans-1-heteradecalins.The allyl ketones were subjected to a homologation-side chain contraction sequence to produce the 6-carbomethoxy-trans-2-heteradecalins.Allylation of 3-carbomethoxycyclohexanone (12) was not regioselective, but all four product isomers were characterized.The desired 5-carbomethoxy-2-allylcyclohexanone isomers (27 and 28) were converted to the 7-carbomethoxy-trans-decalins by similar series of reactions
INTRAMOLECULAR PHOTOCYCLIZATION OF 1-(TRIMETHYLSILYL)-1,5-HEXADIEN-3-ONES
Wilson, Phyllis,Wolff, Steven,Agosta, William C.
, p. 5883 - 5886 (2007/10/02)
An influence upon the regiochemistry of cylization due to a 1-trimethylsilyl substituent is indicated upon comparison of the photochemistry of 4a,b and their carbon analogs 5a,b.
Regiochemical Control in Intramolecular Photochemical Reactions of 1,5-Hexadien-3-ones and 1-Acyl-1,5-hexadienes
Wolff, Steven,Agosta, William C.
, p. 1292 - 1299 (2007/10/02)
Both 1,5-hexadien-3-ones (7) and 1-acyl-1,5-hexadienes (8) generally undergo intramolecular photochemical cyclization by way of 1,5 (crossed) closure (see 2), as do other derivatives of 1,5-hexadienes (1).Through study of the photochemistry of 14 members
A homologous ester claisen rearrangement via the cope rearrangement of O-trimethylsilylcyanohydrins
Ziegler, Frederick E.,Nelson, Richard V.,Wang, Tien-fu
, p. 2125 - 2128 (2007/10/02)
The Cope rearrangement of 1,5-dienyl trimethylsilyl-cyanohydrins to α-trimethylsilyoxy-α,β-unsaturated nitriles and their cleavage to methyl δ-hexenoates is discussed.
