Prodn. of undeca-1,3,5-tri:ene rich in 3E, 5Z isomer, useful as fragrance - by reducing undec-3-yn-5-en-1-ol with metallic reducing agent, converting prod. to active deriv. and heating with base

• Main Authors: GAUDIN, JEAN-MARC, MOREL, CEDRIC
• Format: Patent
• Language: English; French
• Published: 31.08.1992
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; ANIMAL AND VEGETABLE OILS, FATS, FATTY SUBSTANCES AND WAXES; CANDLES; CHEMISTRY; DETERGENTS; ESSENTIAL OILS; FATTY ACIDS THEREFROM; METALLURGY; ORGANIC CHEMISTRY; PERFUMES; PRODUCING (PRESSING, EXTRACTION), REFINING AND PRESERVINGFATS, FATTY SUBSTANCES (e.g. LANOLIN), FATTY OILS AND WAXES,INCLUDING EXTRACTION FROM WASTE MATERIALS

Undec-3-yn-5-en-1-ols of formula (I) (where the wavy line denotes a cis or trans configuration are new. Undeca-3E,5Z-dien-1-ol of formula (II) is also new. Prodn. of prods. comprising at least 80 wt.% undeca-1,3E,5Z-triene (IIIa) and upto 20 wt.% undeca-1,3E,5E-triene comprises (a) reducing (I) with a metallic reducing agent to obtain an isomer mixt. comprising mainly (II), (b) converting the prod. to a reactive deriv. of formula (IV); and (c) treating (IV) with a base. In (IV) X is a leaving gp.. Step (a) is pref. effected with LiAlH4. Step (b) is effected by reaction with mesyl chloride or PBr3 to give (IV) (where x = mesyloxy or Br respectively). Step (c) is effected with an alkali metal hydroxide, alkoxide or hydride or with diazabicyloundecene. Prepn. of (I) is effected by reaction of at least 95% pure (Z)-1-bromo-1-heptene with but-3-yn-1-ol in the presence of a Pd catalyst, esp. Pd(PPh3)2Cl4, and a Cu cocatalyst, e.g. CuCl or CuI. USE/ADVANTAGE - The (IIIa)-rich prods. are fragrances with better aroma characteristics than commercially available undeca-1,3,5-triene prods..