Synthesis of dihydroactiniolide [5,6,7,7a-tetrahydro-4,4,7a-trimethylbenzofuran-2(4H)-one] and 6,7,8,8a-tetrahydro-5,5,8a-trimethylnaphthalene-1,3(5H)-dione from 6,7,8,8a-tetrahydro-2,5,5,8a-tetramethyl-5H-chromen
Autoxidation of 6,7,8,8a-tetrahydro-2,5,5,8a-tetramethyl-5H-chromen (2), obtained by photolysis of β-ionone, afforded a mixture of dihydroactiniolide (4), a cyclohexylideneacetaldehyde (5), and 3,5,6,7,8,8a-hexahydro-2,5,5,8a-tetramethyl-2H-chromen-2,3-diol (6). By refluxing in benzene, compound (6) was converted into a hexahydroindenone (15), which, in several steps, afforded 6,7,8,8a-tetrahydro-5
通过β-紫罗兰酮的光解作用自动氧化6,7,8,8a-四氢-2,5,5,8a-四甲基-5 H-铬烯(2),得到二氢放线碘化物(4),环己叉基乙醛( 5),和3,5,6,7,8,8a-六氢-2,5,5,8a-四甲基-2 H -chromen-2,3-二醇(6)。通过在苯中回流,将化合物(6)转化为六氢茚酮(15),在几个步骤中,得到6,7,8,8a-四氢-5,5,8a-三甲基萘-1,3(5 H) -二酮(20)。
Photochemistry of dienones-VIII
作者:Hans Cerfontain、J.A.J. Geenevasen
DOI:10.1016/s0040-4020(01)92097-6
日期:1981.1
isomerizations of (E)-β-ionone 1, and of mixtures of the isomeric pyran 2 and (Z)-β-ionone 3 in CD3OD as solvent on direct irradiation with λ 254 nm and on triplet photo-sensitization have been studied at temperatures ⩽ - 50°, where the thermal isomerization between 2 and 3 is fully inhibited. The direct irradiation of 1 at -60° leads to 3 and (Z)-retro-γ-ionone 4 as primary products; 3 is subsequently rapidly
作者:Claudio D. Borsarelli、Mirta Mischne、Agustina La Venia、Faustino E. Morán Vieyra
DOI:10.1111/j.1751-1097.2007.00147.x
日期:2007.11
at 355 nm, such as laser‐flash photolysis, photoacoustic and singlet oxygen 1O2 phosphorescence detection, confirmed the formation of the excited triplet state of 1 with a quantum yield ΦT = 0.50 as the precursor for the generation of singlet oxygen 1O2 (ΦΔ = 0.16) and the isomeric α‐pyran derivative (3), which was a reaction intermediate detected by NMR. In turn, the reaction of 1O2 with 1 and 3 occurred