Kinetics of the epoxidation of geraniol and model systems by dimethyldioxirane.

نویسندگان

  • A L Baumstark
  • P J Franklin
  • P C Vasquez
  • B S Crow
چکیده

The mono-epoxidation of geraniol by dimethyldioxirane was carried out in various solvents. In all cases, the product ratios for the 2,3 and 6,7 mono-epoxides were in agreement with literature values. Kinetic studies were carried out at 23 degrees C in the following dried solvent systems: acetone (k(2) = 1.49 M(-1)s(-1)), carbon tetrachloride/acetone(9/1, k(2)=2.19 M(-1)s(-1)), and methanol/acetone (9/1, k(2) = 17 M(-1)s(-1)). Individual k(2) values were calculated for epoxidation of the 2,3 and 6,7 positions in geraniol. The non-conjugated diene system was modeled employing two simple independent alkenes:2-methyl-2-pentene and 3-methyl-2-buten-1-ol by determining the respective k(2) values for epoxidation in various solvents. The kinetic results for each independent alkene showed that the relative reactivity of the two epoxidation sites in geraniol as a function of solvent was not simply a summation of the independent alkene systems.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Immobilized Vanadium Compounds within Nanoreactors of Al-MCM-41 as Catalyst for Epoxidation of Alkenes

VO2+ and its complexes with ethylenediamine (en), acetylacetonate (acac), 2, 2’-bipyridine(bpy) ligands, immobilized within nanoreactors of Al-MCM-41 designated as VO2+/Al-MCM-41 or VOL2/Al-MCM-41, were prepared and characterized by X-ray powder diffraction (XRD), FT-IR, BET nitrogen adsorption-desorption and chemical analysis techniques. VO2+/Al-MCM-41 and VOL2/Al-MCM-41 were found to catalyze...

متن کامل

Stereoselective epoxidation of 4-deoxypentenosides: a polarized-pi model.

The high facioselectivity in the epoxidation of 4-deoxypentenosides (4-DPs) by dimethyldioxirane (DMDO) correlates with a stereoelectronic bias in the 4-DPs' ground-state conformations, as elucidated by polarized-pi frontier molecular orbital (PPFMO) analysis.

متن کامل

Kinetic study of cis-polybutadiene epoxidation by using 1HNMR spectroscopy in buffered oxone® solution with tetra-n-butyl ammonium bromide as phase transfer catalyst (PTC)

Cis-polybutadiene was functionalized using in–situ generated DMD as oxidant and tetra-n-butyl ammonium bromide as phase transfer catalyst (PTC). The epoxidation process was investigated by 1HNMR spectroscopy. 1HNMR spectrum analysis of products confirms the absence of ring opening side products in epoxidation reaction. Various factors such as reaction temperature, reaction time and the concentr...

متن کامل

Expedient Catalytic Access to Geraniol Epoxide Using a New Vanadium Schiff Base Complex on Modified Magnetic Nanoparticles

The Fe3O4@SiO2@APTMS@Glu-His@V complex was prepared with modification of iron oxide magnetic nanoparticles with (3-aminopropyl) trimethoxysilane (APTMS) and glutaraldehyde-L-histidine Schiff base followed by complexation with VOSO4. Characterization of the Fe3O4@SiO2@APTMS@Glu-His@V complex was carried out by means of FTIR, XRD, SEM, EDX, TEM, AAS and VSM techniques. It was found that Fe3O4@SiO...

متن کامل

The role of asynchronous bond formation in the diastereoselective epoxidation of cyclic enol ethers: a density functional theory study.

Density functional theory (DFT) (Becke3LYP functional and the D95 basis set) was used to study the influence of substitution on the dimethyldioxirane epoxidation reaction of six- and seven-membered cyclic enol ethers. In agreement with our previously reported experimental results, the calculations predict that substitution on the cyclic enol ether influences the level of diastereoselectivity. A...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Molecules

دوره 9 3  شماره 

صفحات  -

تاریخ انتشار 2004