5 jul. 1- Dados os compostos de Grignard abaixo, forneça a nomenclatura de cada um deles: a) H3C — CH2— CH2— CH2— MgCl Cloreto de butil-. Keywords: allylic oxidation, selenium dioxide, homoallylic alcohols, Grignard adsorvido em SiO2, propicia uma rota conveniente para tais compostos. O primeiro estudo sistemático sobre os compostos organoestânicos (OTs, .. tetrassubstituído via reação de “Grignard” (brometo ou cloreto de etil, butil ou.
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The composfo was stirred at ambient temperature for 8 h and then diluted with 30 mL of ether. To improve the low composot that was obtained for the oxidation of 8we investigated a new route to reach 9. A new sequence was investigated with another substrate in an attempt to improve the yield of the desired phenol-alcohol 9 Scheme 4.
Kascheres on occasion of his 60 th birthday. Then a solution of 2 E – 3,7-dimethyl-2,6-octadienyl tetrahydro-2 H pyranyl ether 12 After stirring for 15 min at room temperature, cold pentane 25 mL was added, and the organic layer was washed with cold water, extracted with pentane 2×25 mL and then washed with brine. Tetrahydro-2 H pyranyl ether 7 3.
Scheme 2 shows the first attempt. Completion of the reactions was established by TLC analysis. Also, we developed an efficient synthesis of 2-geranylphenol derivatives via a Cu I -mediated Grignard coupling of 2-lithiophenols and geranyl substrates.
The ether phase was washed with water 30 mLthen with brine 2×30 mLdried over MgSO 4filtered and the solvent was removed under reduced pressure by rotatory evaporation. The organic layer was then dried over MgSO 4filtered and the solvent was removed under reduced pressure.
Difunctional allylic terpenes are important synthetic building blocks. Economic Entomology81 Nova22 Also, an efficient synthesis of 2-geranylphenol derivatives via a Cu I -mediated Grignard coupling of 2-lithiophenols and geranyl substrates was developed. To a two-necked mL round bottom flask with 2-iodophenyl tetrahydropyranyl ether 6 3.
Our target was to obtain 2-[ 2 E ,6 E -3,7-dimethylhydroxy-2,6-octadienyl]phenol 9 by optimizing the coupling of geranyl acetate derivatives with more appropriate reagent O -protected 2-iodophenol.
How to cite this article. To a solution of 10 3.
Economic Entomology79 ggrignard, However, “nontarget” organisms may be exposed, resulting in the poisoning of biological system, originating mutations and sentencing species to extinction. The mixture was treated drop wise with cold metanol 1 mL and extracted with hexane. The same procedure as employed for allylic oxidation of 1 was used ; compound 13 3. The geignard layer was washed with two portions of brine then dried with anhydrous MgSO 4.
Preparative column chromatography was carried using silica gel 60 Merckmesh. After the disappearance of the starting material, water 30 mL was added and the mixture was extracted with dichloromethane 2×30 mL. The same procedure employed for the allylic oxidation of 1 was used; compound 8 2.
Ggignard studies on phenolic oxidation of these synthetic intermediates to achieve the synthesis of cyclic isoprenoids will be reported in due course.
After the temperature reached room temperature, CuI 1. New York,p. S New York,vol.
To a stirred solution of 14 3. Preparation of aromatic geraniol analogues via a Cu I -mediated Grignard coupling.
Preparation of aromatic geraniol analogues via a Cu(I)-mediated Grignard coupling
Services on Demand Journal. Emo consumo de OTs era estimado em cerca de toneladas por ano 3. After 30 min, geranyl bromide 2. The chosen protecting groups clearly influence the oxidation process. Using lower molar quantities of SeO 2 should reduce selenium by-products, facilitating the purification of selenium-free products. The reaction was cooled, a saturated solution of NH 4 Cl was added, the solutions was extracted with ether 3×50 mLdried over MgSO 4filtered and the solvent was removed under reduced pressure by rotatory evaporation.
Naturstoffe22 After allowing the reaction mixture to reach ambient temperature, CuI was added followed by the addition of allylic alcohol 2. Conclusion Composyo brief, we optimized a selective oxidation of allylic methyl groups in geraniol derivatives over a solid support to the corresponding trans- ab -unsaturated alcohols and aldehydes, using selenium dioxide and t -butylhydroperoxide adsorbed on silica gel as oxidants.
In a three necked round bottom flask, tert -butyldimethylsilyl 2-iodophenol ether 11 3. Bromination of geraniol 15 with phosphorus tribromide 0. Environmental contamination for organotin compounds. To stirred solution of 1.
The solvent was removed under vacuum and the residue was diluted in ether 50 mL and water 30 mLthen extracted with ether 2×30 mLdried over MgSO 4 and com;osto, and then the solvent was removed under reduced pressure.
This result was still not satisfactory so we tried a different approach. Services on Demand Journal.