tert-Butanol → HCID 86741466, compound

Temperature

-25 °C

In a sulphonation flask equipped with a stirrer, a thermometer, a dropping funnel, a reflux condenser and an apparatus for inert gasification 16 ml of tert.butanol and 20 ml of absolute toluene were placed under argon and cooled to -25° C. This solution was treated dropwise at -30° C. to -20° C. within 10 minutes with 52 ml of a 1.56M solution of butyl lithium in hexane and the mixture was stirred for a further 30 minutes without cooling. There was subsequently added to the thus-prepared solution of lithium tert.-butylate at about 20° C. in one portion a solution of 14.4 g of (1S,4R,6R)-4-hydroxy-1-(5-hydroxy-3-methyl-3E-penten-1-ynyl)-2,2,6-trimethylcyclohexyl benzoate in 120 ml of absolute toluene. The suspension obtained was heated carefully to 65° C. with the aid of an oil bath and stirred at this temperature for 1.5 hours. Thereafter, the mixture was poured on to 150 ml of ice/water. The aqueous phase was separated and extracted twice with 150 ml of diethyl ether each time. The organic phases were washed with 150 ml of saturated sodium chloride solution, combined, dried over sodium sulphate and concentrated on a rotary evaporator at about 40° C. and the residue was then dried at room temperature for 1 hour in a high vaccum. The crude product obtained (12.0 g) was chromatographed on silica gel with diethyl ether/hexane (vol. 1:1). From the product-containing fractions there was obtained a total of 7.5 g (80%) of (4R)-5-(4-hydroxy-2,6,6-trimethyl-1-cyclohexen-1-yl)-3-methyl-2E-penten-4-yn-1-ol as yellowish crystals (purity 98.8%, content of 2Z isomer 1.1%).

1. customIn a sulphonation flask equipped with a stirrer
2. temperaturewithout cooling
3. customThe suspension obtained
4. temperaturewas heated carefully to 65° C. with the aid of an oil bath
5. stirringstirred at this temperature for 1.5 hours
6. customThe aqueous phase was separated
7. extractionextracted twice with 150 ml of diethyl ether each time
8. washThe organic phases were washed with 150 ml of saturated sodium chloride solution
9. dry with materialdried over sodium sulphate
10. concentrationconcentrated on a rotary evaporator at about 40° C.
11. customthe residue was then dried at room temperature for 1 hour in a high vaccum
12. customThe crude product obtained (12.0 g)
13. customwas chromatographed on silica gel with diethyl ether/hexane (vol. 1:1)

ORD record

ord-8252a590c8ae4ff0a29a0549027dd62a

Source dataset

uspto-grants-1987_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04661641