Easy Epoxidation of Monoterpenes from Common Starting Materials
摘要:
Epoxidation of monoterpenes, alpha-pinene, beta-pinene, limonene, alpha-terpinene, and (R)-carvone was carried out by the in situ production of a peroxyacid rather than direct addition of such an expensive and difficult to handle chemical. Previous reports showed use of metal catalysts with high yields, while methodologies without catalysts at high temperature showed yields lower than 30%. The authors report a methodology that produces peroxyacetic acid in situ yielding up to 75% pure epoxide at room temperature avoiding the use of catalysts. The products were analyzed by gas chromatography mass spectrometry (GC-MS), and structures were characterized by H-1 and C-13 nuclear magnetic resonance (NMR).
Competitive Reactions of Diene Cation Radicals Formed on Irradiated Metal Oxide Surfaces
作者:Marye Anne Fox、Debra D. Sackett、Janet N. Younathan
DOI:10.1016/s0040-4020(01)90277-7
日期:1987.1
which involves the intermediacy of a diene cationradical generated by transfer of an electron from the adsorbed diene to a photogenerated hole localized at the surface of the excited TiO2 particle. Non-oxidative cleavage products are also observed, and the effect of the semiconductor surface in controlling reactivity of the photogenerated cationradical is discussed. The first examples of aromatization
Oxygenated derivatives of menthatriene in parsley leaves
作者:Siegfried Nitz、Hubert Kollmannsberger、Martin H. Spraul、Friedrich Drawert
DOI:10.1016/0031-9422(89)80278-x
日期:1989.1
revealed the presence of two novel oxygenated p -mentha-1,3,8triene derivatives, the amounts of which increase during processing of plant material and deteriorate the typical fresh aroma. The two derivatives, which could be synthesized by means of a dye sensitized photooxygenation reaction, were identified as 1-methyl-4-(methylethenyl)-2,3-dioxabicyclo[2.2.2]oct-5-ene and 4-methyl-7-(methylethenyl)-3