Telomerisation of conjugated alkadiene with sugar in aq. sec. or tert. alkanol - with palladium catalyst, with initial addn. of part of alkadiene, heating and continuous addn. of remaining alkadiene

摘要

Telomerisation of conjugated alkadiene with sugar involves (a) prepn. of mixt. contg. sugar, solvent comprising saturated aliphatic sec. or tert. alcohol and water, catalytic amt. of Pd catalyst and part of the alkadiene, (b) heating the mixt. to 40-100 deg.C, and (c) continuous addn. of the remaining amt. of alkadiene, keeping the temp. at 40-100 deg. Pref. the sugar is mono- or di-saccharide, the alkadiene is 4-20C (un)branched aliphatic diene or 5-8C cyclic alkadiene, pref. 1,3-butadiene, piperylene and/or isoprene, partic. 1,3-butadiene. Water forms 0.5-30 (10-15) wt.% of the reaction solvent. The catalyst is Pd(II) acetylacetonate with 2 equivs. of Ph3P as ligand (pref.), Pd(II) acetate with 2 equivs. of Ph3P as ligand, Pd(II) chloride with 2 equivs. of Ph3P as ligand or tetrakis(triphenylphosphine) Pd, in molar ratio of catalyst:alkadiene or 1:10,000-100,000. Reaction is at 60-80 deg.C, with 2-propanol as sec. alcohol. Pref. sugars are glucose, a 1-10C alkylglucoside (esp. methylglucoside), sucrose or sorbitol. USE/ADVANTAGE - The prods. are sugar-alkadienyl ethers, useful as emulsifiers, lubricants, thickeners, tensides and components of cosmetics. The process can be operated commercially, and gives high yields, with redn. of the formation of alkadiene dimers and alkadiene dimer ethers of the alcohol