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11.
Citral extracted from Cymbopogon citratus (Gramineae) was subjected to photochemical epoxidation with hydrogen peroxide to obtain a mixture of epoxy derivatives at the C2=C3 and C6=C7 double bonds. The thermal oxidation of citral with m-chloroperoxybenzoic acid at room temperature gave only the corresponding 6,7-epoxy derivative as a mixture of E and Z isomers with respect to the C2=C3 double bond. Photosensitized oxygenation of citral in the presence of tetraphenylporphyrin, Rose Bengal, or chlorophyll lead
to a mixture of two isomeric hydroperoxides, (2E)-6-hydroperoxy-3,7-dimethylocta-2,7-dienal and (2E,5E)-7-hydroperoxy-3,7-dimethylocta-2,5-dienal. Epoxidation of pulegone isolated from Penny royal oil (Mentha pulegium, Lamiaceae) with hydrogen peroxide under irradiation with a sodium lamp lead to a mixture of cis- and trans-isomeric 2,2,6-trimethyl-1-oxaspiro[2.5]octan-4-ones, whereas under conditions of photosensitized oxygenation two hydroperoxide
derivatives, 2-(1-hydroperoxy-1-methylethyl)-5-methylcyclohex-2-en-1-one and 2-hydroperoxy-5-methyl-2-(1-methylethenyl)cyclohexan-1-one,
were also formed. Camphene reacted with hydrogen peroxide under irradiation to give a mixture of the corresponding endo- and exo-epoxy derivatives and camphor, while its thermal oxidation with m-chloroperoxybenzoic produced only the two former.
Published in Russian in Zhurnal Organicheskoi Khimii, 2008, Vol. 44, No. 6, pp. 825–833.
The text was submitted by the authors in English. 相似文献
12.
Weber T Khayyat K Dörner R Rodríguez VD Mergel V Jagutzki O Schmidt L Müller KA Afaneh F Gonzalez A Schmidt-Böcking H 《Physical review letters》2001,86(2):224-227
We report on the experimental observation of an abrupt rise in the longitudinal momentum distribution of recoil ions created in proton helium collision. The details of this structure can be related to electrons traveling with the velocity of the projectile [electron capture to the continuum (ECC)]. The longitudinal as well as the transverse distribution of the recoil ions can be explained as a continuation of the momentum distribution from ions resulting from electron capture illustrating the smooth transition from the capture to bound states of the projectile to the ECC. 相似文献
13.
Suzan A. Khayyat 《Journal of Saudi Chemical Society》2013,17(1):61-65
It has been reported that trans-cinnamaldehyde, eugenol and safrole inhibited bacteria and fungi growth in vivo mode. In order to improve their biological activity, dimeric cinnamaldehyde, eugenol and safrole have been photosynthesized. The photosynthesis compounds were 4,6-diphenyl-1,2-dioxane-3,5-dicarboxaldehyde, 4,4-(cyclobutone-1,3-diyl bis(methylene))bis(2-methoxyphenal), and 3,6-bis(benzo[d][1,3]dioxol-5-ylmethyl)-1,2-dioxane. These new dimeric compounds strongly inhibited Candida albicans growth more than the monomers. 相似文献