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 mixture was stirred at ambient temperature for 8 h and then diluted with 30 mL of ether. After 30 min, geranyl bromide 2. Nova22 Introduction A wide variety of phenolic natural products contain isoprenoid residues. The solvent was compostto under reduced pressure and the residue was diluted with ether 50 mL and water 30 mL and extracted with ether 2×50 mL.
Naturstoffe22 The organic layer was then dried over MgSO 4filtered and the solvent was removed under reduced pressure. To improve the low yield that was obtained for the oxidation of 8we investigated a new route to reach 9. Scheme 2 shows the first attempt. Then a solution of 2 E – 3,7-dimethyl-2,6-octadienyl tetrahydro-2 H pyranyl ether 12 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.
Acta, The same procedure as employed for the coupling of 11 and 12 was usedstarting with tert -butyldimethylsilyl 2-iodophenol ether 11 3. Economic Entomology81 Services on Demand Journal. To a solution of 10 3. Completion of the reactions was established by TLC analysis. C -geranyl and C -farnesyl phenols have been prepared by reaction of geranyl or farnesyl bromide with the sodium salt of the phenol.
All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License. The mixture was treated drop wise with cold metanol 1 mL and extracted with hexane. 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.
Em Organotin Compounds ; Sawyer, A. Conclusion In 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. Kascheres on occasion of his 60 th birthday. The same procedure as employed for allylic oxidation of 1 was used ; compound 13 3. Bromination of geraniol 15 with phosphorus tribromide 0.
New York,p. Alkylation of sodium salts, however, invariably leads to complex mixtures containing both ring and oxygen substituted products.
A new sequence was investigated with another substrate in an attempt to improve the yield of the desired phenol-alcohol 9 Scheme 4. How to cite this article. The occurrence and the effects of organotin compounds OTs have been studied since a long time, due to their widespread use and deleterious effects.
The same procedure employed for the allylic oxidation of 1 was used; compound 8 2. To a stirred solution of 14 3. Grignarf a solution of 2-iodophenol 2.
The extracts were washed with a saturated aqueous solution of FeSO 4. Some OTs are used as pesticides in crops, or as biocides in antifouling paints, applied in the ship hulls to avoid attachment and growth of tube worms, mussels and barnacles. The Sharpless conditions for oxidation of geranyl acetate employs 0. Geraniol was purchased from Aldrich Chem. New York,vol.
Fall30 Also, we developed an efficient synthesis of 2-geranylphenol compostl via a Cu I -mediated Grignard coupling of 2-lithiophenols and geranyl substrates. Economic Entomology79 After the temperature reached room temperature, CuI 1.
Services on Demand Journal. Environmental contamination for organotin compounds. The mixture was stirred for 48 h.
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Also, an efficient synthesis of 2-geranylphenol derivatives via a Cu I -mediated Grignard coupling of 2-lithiophenols and geranyl substrates was developed. 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 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 filtered, and then the solvent was removed under reduced pressure.
February 4, Published on the web: Further studies on phenolic oxidation of these synthetic intermediates to achieve the synthesis of cyclic isoprenoids will be reported in ee course.
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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. Results and Discussion The Sharpless conditions for oxidation of geranyl acetate employs 0.
In a three necked round bottom flask, tert -butyldimethylsilyl 2-iodophenol ether 11 3. After allowing the reaction mixture to reach ambient temperature, CuI was added followed by the gribnard of allylic alcohol 2.