beta-Cyclocitral → 2,6,6-TRIMETHYL-alpha-ISOPROPENYL-1-CYCLOHEXENE-1-METHANOL

Temperature

20 °C

Into a 500 ml flask equipped with immersion thermometer, mechanical stirrer, 250 ml addition funnel, Friedrich's condenser, dry-ice/isopropyl alcohol bath and gas bubbler is placed 1.9 grams (44.7 cm in length) (0.28 gram atoms) of cut up lithium wire and 100 ml anhydrous diethyl ether. The lithium/diethyl ether mixture is cooled to -10° C. 15.7 Grams (0.13 moles) of 2-bromo-1-propene (dissolved in approximately 40 ml anhydrous diethyl ether) is added drop-wise to the reaction mass keeping the temperature at between -10° C. and -5° C. Following addition of the 2-bromo-1-propene, the reaction mass is stirred for a period of 30 minutes at 0° C. and for a period of 1.5 hours at room temperature (20° C.). The reaction mass is then chilled to -20° C. and 15.2 grams (0.10 moles) of beta cyclocitral dissolved in approximately 60 ml diethyl ether) is added dropwise while keeping the reaction temperature at between -20° C. and -15° C. After addition of the beta cyclocitral, the reaction mass is stirred for a period of 15 minutes at -20° C.; and for a period of 120 minutes at +24° C. The reaction mass is then poured into a saturated aqueous ammonium chloride solution, and the resulting organic phase is separated from the aqueous phase. The aqueous phase is washed with anhydrous diethyl ether. The organic phase is washed with saturated brine. The organic phase and the ether extracts are combined and the resulting material is dried and concentrated to yield 19.98 grams of crude material. This material is distilled under vacuum to 5 fractions as follows:

1. customat between -10° C. and -5° C
2. temperatureThe reaction mass is then chilled to -20° C.
3. additionis added dropwise
4. customat between -20° C. and -15° C
5. stirringthe reaction mass is stirred for a period of 15 minutes at -20° C.
6. waitand for a period of 120 minutes at +24° C
7. customthe resulting organic phase is separated from the aqueous phase
8. washThe aqueous phase is washed with anhydrous diethyl ether
9. washThe organic phase is washed with saturated brine
10. customthe resulting material is dried
11. concentrationconcentrated

ORD record

ord-3a70ae5bb53f465884f367100cac40a2

Source dataset

uspto-grants-1981_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04255293