Reaction #6716

Reaction equation

mesylate

Ethyl 6-methylsulfonyloxyhexanoate

Sodium hydride

alcohol

Hexaethylene glycol monobenzyl ether

NaH

→

product

Yield 44.0%

6-{2-[2-(2-{2-[2-(2-Benzyloxyethoxy)ethoxy]ethoxy}-ethoxy)-ethoxy]-ethoxy}-hexanoic acid ethyl ester

Yield 44.0%

Solvents

toluene

toluene

toluene

Conditions

Workup

1. 1
   Temperaturecooled in an ice bath
2. 2
   Otherto come to room temperature
3. 3
   workup.STIRRINGstirred for another five hours, during which time the mixture
4. 4
   workup.STIRRINGthe combined solutions were stirred at room temperature for three days
5. 5
   OtherThe reaction mixture was quenched with 50 ml methanol
6. 6
   Filtrationfiltered through basic alumina
7. 7
   ConcentrationThe filtrate was concentrated in vacuo
8. 8
   Otherpurified by flash chromatography (silica gel, gradient elution: 3/1 ethyl acetate/hexanes to ethyl acetate)

Procedure

Sodium hydride (3.225 g or a 60% oil dispersion, 80.6 mmol) was suspended in 80 ml of anhydrous toluene, placed under a nitrogen atmosphere and cooled in an ice bath. A solution of the non-polydispersed alcohol 16 (27.3 g, 73.3 mmol) in 80 ml dry toluene was added to the NaH suspension. The mixture was stirred at 0° C. for thirty minutes, allowed to come to room temperature and stirred for another five hours, during which time the mixture became a clear brown solution. The non-polydispersed mesylate 17 (19.21 g, 80.6 mmol) in 80 ml dry toluene was added to the NaH/alcohol mixture, and the combined solutions were stirred at room temperature for three days. The reaction mixture was quenched with 50 ml methanol and filtered through basic alumina. The filtrate was concentrated in vacuo and purified by flash chromatography (silica gel, gradient elution: 3/1 ethyl acetate/hexanes to ethyl acetate) to yield the non-polydispersed product as a pale yellow oil (16.52 g, 44%). FAB MS: m/e 515 (M+H).

Source