Acetaldehyde → 2-Phenylethanol

Temperature

-40 °C

Triphenylphosphine (8.4 g.) and potassium carbonate (4.9 g.) were added to a stirred solution of 2-[p-(2-bromoethyl)phenyl]ethyl tetrahydropyranyl ether (10 g.) in acetonitrile (200 ml.) and the mixture was heated under reflux for 36 hours, cooled and filtered. The filtrate was evaporated to dryness and the residue was purified by chromatography on a silica gel column using a 10:1 v/v mixture of methylene chloride and methanol as eluant. n-Butyllithium (1.2 ml. of a 1.5 molar solution in hexane) was added to a stirred solution of the phenethyltriphenylphosphonium bromide thus obtained (1.1 g.) in tetrahydrofuran (5 ml.) which was maintained at -40° C. under an atmosphere of argon, and a solution of the above acetaldehyde (0.2 g.) in tetrahydrofuran (5 ml.) was added. The reaction mixture was stirred at -40° C. for 18 hours, allowed to warm up to laboratory temperature and saturated aqueous ammonium chloride solution (10 ml.) was added. The mixture was extracted three times with diethyl ether (10 ml. each time) and the combined extracts were washed with water, dried and evaporated to dryness. The residue was purified by chromatography on a silica gel column using a 3:1 v/v mixture of petroleum ether (b.p. 40°-60° C.) and diethyl ether as eluant. The product thus obtained was hydrogenated over a palladium- on-charcoal catalyst by a similar process to that decribed in the second part of Example 3, and the tetrahydropyranyl group was removed by acidic hydrolysis by a similar process to that described in the fifth paragraph of Example 2. There was thus obtained as an oil 2-p-{4-[(1RS, 2SR)-6-methoxy-2-p-methoxyphenyl-1,2,3,4-tetrahydronaphth-1-yl]butyl}(phenylethanol.

1. temperaturethe mixture was heated
2. temperatureunder reflux for 36 hours
3. temperaturecooled
4. filtrationfiltered
5. customThe filtrate was evaporated to dryness
6. customthe residue was purified by chromatography on a silica gel column
7. additiona 10:1 v/v mixture of methylene chloride and methanol as eluant
8. additionof a 1.5 molar solution in hexane) was added to a stirred solution of the phenethyltriphenylphosphonium bromide
9. customthus obtained (1.1 g.) in tetrahydrofuran (5 ml.) which
10. additionwas added
11. extractionThe mixture was extracted three times with diethyl ether (10 ml
12. washeach time) and the combined extracts were washed with water
13. customdried
14. customevaporated to dryness
15. customThe residue was purified by chromatography on a silica gel column
16. additiona 3:1 v/v mixture of petroleum ether (b.p. 40°-60° C.) and diethyl ether as eluant
17. customThe product thus obtained
18. customthe tetrahydropyranyl group was removed by acidic hydrolysis by a similar process to that

ORD record

ord-1f9f256fd7e749ebb6708b81d4079e0e

Source dataset

uspto-grants-1988_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04732912