108059-85-4Relevant articles and documents
Comparison of photoenolization and alcohol release from alkyl-substituted benzoyl benzoic esters
Muthukrishnan, Sivaramakrishnan,Pace, Tamara C.S.,Li, Qian,Seok, Brian,De Jong, Gerdien,Bohne, Cornelia,Gudmundsdottir, Anna D.
experimental part, p. 331 - 338 (2011/06/22)
Photolysis of 1B in argon-saturated solutions yields 4B and releases methanol. Laser flash photolysis of 1B shows formation of biradical 2B, which has a lifetime of ～50 ns and a max at 330 nm. Biradical 2B undergoes an intersystem crossing to form photoenols E-3B and Z-3B with a max at 390 nm. Laser flash photolysis shows that the lifetimes of E-3B and Z-3B are affected by the solvent. Density functional theory calculations demonstrate that the transition-state barrier for a 1,5-H atom shift from Z-3B to regenerate 1B is affected by the ortho-alkyl substituents, whereas the stereoelectronics of the alkyl substituent affect the transition-state barrier of E-3B as it undergoes electrocyclic ring closure to form 4B. The photoreactivity of 1B was compared with its analogous methyl and isopropyl derivatives 1A and 1C, respectively,to better estimate the effect of the alkyl substituent on reactivity.
Dibenzocyclooctene-, Dibenzochalcocine-, and Diarenochalconinediones
Hellwinkel, Dieter,Bohnet, Siegbert
, p. 1151 - 1174 (2007/10/02)
2,2'-Oxybis-, -thiobis-, and -methylenebisbenzoic esters 2a-c react with methyllithium in ether to give low yields of 5H-dibenzochalcocine-5,7(6H)-diones 6a, 7a, and dibenzocyclooctene-5,7(6H,12H)-dione (8), respectively.Very good yields of such heterocycles with oxygen (6a-h, 37), sulfur (7a-h, 38) and selenium (36) as key atom are obtained when diaryl ethers (21, 22, 25), -sulfides (27, 29, 30), and -selenides (33) that contain 2'-acetyl- (or -propionyl-) and 2-methoxycarbonyl groups are treated with sodium hydride in boiling toluene.Analogously are prepared the dibenzoxonine-11,13(6H,12H)diones 62a-c and 7H-benzonaphthothionine-7,9-(8H)-dione (65) which are expanded by one ring member.In the analogous reaction of a corresponding benzophenone derivative 35, spiro-3(2H),3'-dione (41) is formed in a tandem reaction. - Under phase transfer conditions the dibenzochalcocinediones 6, 7, 36 and also the corresponding nitrogen cycles 5 react to give mixtures of C- (42-45) and O-alkyl derivatives (46-49).Methyllithium and diisobutylaluminium hydride provide the carbinols 50-54.With bromine and SO2Cl2, respectively, the methylene group is mono- or dihalogenated to the products 56, 57; defined nitration was only possible for the oxacycle 6a.
