88959-02-8Relevant academic research and scientific papers
Oxidation of Alkyl Phenyl Selenides, Tellurides, and Telluroxides with meta-Chloroperbenzoic Acid for a Facile and Novel Transformation of C-Se and C-Te Bonds to C-O Bonds
Uemura, Sakae,Fukuzawa, Shin-ichi
, p. 471 - 480 (2007/10/02)
In sharp contrast to the well-known selenoxide elimination leading to olefins, the treatment of alkyl phenyl selenides (PhSeR) with an excess of meta-chloroperbenzoic acid (MCPBA; 2-5 equiv. to a selenide) in alcohol at room temperature affords the corresponding dialkyl ethers by the substitution of a phenylselenium (PhSe) moiety with an alkoxy group.A similar reaction proceeds by using alkyl phenyl tellurides (PhTeR) and telluroxides , a facile substitution of PhTe or PhTe(O) moiety by an alkoxy group being observed.Methanol is the most appropriate solvent for these oxidations and alkyl methyl ethers are formed in excellent yields.The reaction is accompanied by phenyl migration when applied to some selenides, tellurides, and telluroxides having a phenyl group at a vicinal position to the PhSe, PhTe, or PhTe(O) moiety.Application to the methoxyselenation and methoxytelluration products of cyclohexene and cycloheptene results in a ring-contraction to afford the dimethyl acetals of cyclopentane- and cyclohexane-carbaldehyde, respectively.In case of an allylic phenyl selenide, a sigmatropic rearrangement giving a rearranged allylic alcohol occurs in much preference to the substitution by the methoxy group.Other oxidizing agents than MCPBA such as NaIO4, H2O2, t-BuOOH, and ozone are generally ineffective under similar conditions.It is proposed that the reaction mainly takes place as follows.Alkyl phenyl selenone, alkyl phenyl tellurone, or the MCPBA addition product to them is formed as a reactive intermediate in which an alkyl C-Se or alkyl C-Te bond fission occurs heterolytically by a nucleophilic attack of alcohol, sometimes accompanied by a 1,2-shift of the β-substituent, i.e., phenyl migration and ring-contraction.
A Novel, Simple Method for Transformation of C-Se to C-O Bonds
Uemura, Sakae,Fukuzawa, Shin-ichi,Toshimitsu, Akio
, p. 1501 - 1502 (2007/10/02)
Oxidation of alkyl phenyl selenides with m-chloroperbenzoic acid in methanol at room temperature affords the corresponding alkyl methyl ethers almost quantitatively, the reaction being accompanied by phenyl migration and ring-contraction respectively when applied to selenides having a phenyl group vicinal to the phenylselenium moiety and to some methoxyselenation products of cyclic olefins.
Mode of Metabolism of 1-Tetradecene by Candida Yeasts and Citrates Production
Terasawa, Masato,Takahashi, Joji
, p. 2433 - 2442 (2007/10/02)
Metabolic pathways for the oxidation of 1-tetradecene by Candida lipolytica were investigated and compared with those for Candida tropicalis in oder to elucidate the difference in the productivity of citrates reported in the previous paper.No difference was found in the pathways for the initial stage of oxidation of 1-tetradecene between the two strains, indicating that the difference in the productivity of citrates is not attributable to the metabolic pathways.The metabolic rate of 1-tetradecene with C. lipolytica was found to be much lower than that with C. tropicalis.The production of citrates was much enhanced in the presence of surfactants which were known to be stimulative for microbial metabolism of hydrocarbons and 11-15 g/liters was attained on the 6th day of cultivation.
