3-Methyl-1-pentyn-3-ol → 3,6-Dimethyl-4-octyne-3,6-diol

Temperature

-78 °C

A solution of 3-methyl-1-pentyn-3-ol (30 g, 0.3 mol) in tetrahydrofuran (250 ml) is cooled to −78° C. under a nitrogen atmosphere and n-butyl lithium (1.6 molar solution in hexanes, 383 ml, 0.611 mol) is added slowly over 1.5-2.0 hours. The reaction mixture is stirred for 1 hour at −78° C. and a solution of 2-butanone (41 ml, 0.458 mol) in tetrahydrofuran (50 ml) is added. The reaction mixture is stirred at −78° C. for one hour, allowed to come to ambient temperature and stirred for 2-3 hours. The reaction mixture is cooled to 10° C. and quenched with ice cold water. The aqueous phase is extracted with dichloromethane (3×200 ml). The organic phases are combined, washed with water, and dried over anhydrous sodium sulfate. The mixture is filtered, and the filtrate is evaporated under reduced pressure. The residue is purified by column chromatography on silica gel to give 3,6-dimethyloct-4-yne-3,6-diol (27 g) as a colourless oil.

1. stirringThe reaction mixture is stirred at −78° C. for one hour
2. customto come to ambient temperature
3. stirringstirred for 2-3 hours
4. temperatureThe reaction mixture is cooled to 10° C.
5. customquenched with ice cold water
6. extractionThe aqueous phase is extracted with dichloromethane (3×200 ml)
7. washwashed with water
8. dry with materialdried over anhydrous sodium sulfate
9. filtrationThe mixture is filtered
10. customthe filtrate is evaporated under reduced pressure
11. customThe residue is purified by column chromatography on silica gel

ORD record

ord-9fd79e0f4da949948d43f4d5c5658a37

Source dataset

uspto-grants-2014_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08895761B2