Reaction #214746

Reaction equation

chloride

n-Butyllithium

6,6-Ethylenedioxy-2-methyl-heptanol

tetrahydrofuran

Methoxyethoxymethyl chloride

→

6,6-ethylenedioxy-1-methoxyethoxymethoxy-2-methylheptane

Conditions

Workup

1. 1
   Temperaturethe solution is warmed to 0° C
2. 2
   workup.STIRRINGstirring
3. 3
   workup.WAITis continued at 0° C. for 2 hours
4. 4
   OtherThe tetrahydrofuran is evaporated in vacuo
5. 5
   Otherthe residue is partitioned between ether and brine
6. 6
   ExtractionThe ether extract
7. 7
   Dryingis dried (Na2SO4)
8. 8
   Otherthe solvent is evaporated in vacuo

Procedure

6,6-Ethylenedioxy-2-methyl-heptanol (2.0 g) is dissolved in anhydrous tetrahydrofuran (35 ml) and cooled to -78° C. under nitrogen. n-Butyllithium (0.68 g) is added and the solution is warmed to 0° C. Methoxyethoxymethyl chloride (1.59 g) is added and the reaction stirred at 0° C. for 1.5 hours. An additional 1.59 g of the chloride is added and stirring is continued at 0° C. for 2 hours. The tetrahydrofuran is evaporated in vacuo and the residue is partitioned between ether and brine. The ether extract is dried (Na2SO4) and the solvent is evaporated in vacuo to give 6,6-ethylenedioxy-1-methoxyethoxymethoxy-2-methylheptane. The compound is dissolved in acetone (40 ml) and 10% hydrochloric acid (2.0 ml) is added and the resulting solution is stirred for two hours. A saturated sodium bicarbonate solution (50 ml) is added, and the resulting precipitate filtered and the filtrate evaporated in vacuo. The residue is partitioned between ether and brine and the ether extract is dried (Na2SO4) and evporated in vacuo. The residue is chromatographed on silica (solvent: ethyl acetate/hexane) to give 1-methoxyethoxymethoxy-2-methyl-6-oxo-heptane as a colorless liquid, nmr (CDCl3,δ) 0.9 (d, CH3CH), 2.12 (s, CH3C=O), 2.4 (t, --CH2C=O, 3.3-3.8 (m, --OCH3, ##STR44## --OCH2CH2O), 4.66 (s, 2H, --OCH2O--).

Source