1-PENTANOL, 3-METHYL-5-PHENYL is a colorless liquid, bp0.013 kPa 86–91 °C, d20
20 0.960–0.964,
n20
D 1.511–1.514, with a long-lasting diffusive, fresh, floral, rose odor.The alcohol
is prepared by hydrogenation of tetrahydro-4-methylene-5-phenylpyran, which is
obtained by cyclocondensation of benzaldehydewith 3-methyl-3-buten-l-ol in the
presence of p-toluenesulfonic acid.
It can be used in all perfume types for a wide range of products, for example,
soaps, detergents, and body care products.
A. Benzaldehyde, tert-butylbenzene, iron sulfate, and isopentenol react at 150-155C with water removal to yield phenyl dihydropyran.
B. The oil phase is distilled under reduced pressure to isolate phenyl dihydropyran and recover tert-butylbenzene.
C. Phenyl dihydropyran is partially hydrogenated using Raney Nickel at 130C and 0.6-1 MPa.
D. The filtrate is further hydrogenated to completion using Pd/C at 130-140C and 0.7-1 MPa.
E. The hydrogenated material is worked up and distilled under reduced pressure to obtain the product.
