L,5-Hexadiene-3-ols

The l,5-hexadien-3-ol derivatives 792 and 794 are cycli2ed to form the cyclo-pentadiene derivatives 793 and 795 by insertion of an alkene into -allylpalla-dium formed from allylic alcohols in the presence of trifluoroacetic acid (lO mol%) in AcOH[490],... 

Hexachlorobenzene, conversion to pen-tachlorobenzoic acid, 44, 78 Hexachlorocyclopentadiene, ethylation to l,2,3,4,5-pentachloro-5-ethyl-cyclopentadiene, 43, 90 Hexadecanedioic acid, 43,39 l,5-Hexadien-3-ol, 41, 49... 

Phosphorus pentachloride, for conversion of pentaacetylgluconic add to add chloride, 41, 80 for oxidation of cycloheptatriene to tropylium fluoborate, 43, 101 with cyanoacetic acid, 41, 5 Phosphorus tribromide, reaction with l,5-hexadien-3-ol, 41, 50 Phthalic acids from thioimides, 44, 93 Phthalic anhydride, reaction with L-phenylalanine to yield N-phthaiyi-L-phenylalanine, 40, 82 Phthalic monoperacid, 42, 77 Phthaionic acid, 44, 63 N-Phthalyl-L-alanine, 40, 84 N-Phthalyl-0-alanine, 40, 84 N-Phthalylglydne, 40,84 N-Phthalyl-l-/3-phenylalanine, 40,82 PlMELIC ACID, (S-OXO-, DIETHYL ESTER, 42,41... 

Determination of both relative and absolute configuration of 14 obtained from rac-4-ben-zoyl-l,5-hexadien-3-ol by Sharpless epoxidation (see p420), by conversion into D-( + )-digi-toxose (15)137,... 

The moist crude bromohexadiene is quaternized in water without further purification. The submitters report that, if desired, the crude mixture may be dried over anhydrous calcium chloride and fractionally distilled through a 10-in. stainless-steel-packed column at reduced pressure. Crude bromohexadiene (220-230 g.) from 147 g. (1.50 moles) of l,5-hexadiene-3-ol was found to give the fractions listed in Table I. The yield of the... 

Oxy-Cope rearrangement (cf. 10, 31). Tertiary substituted l,5-hexadiene-3-ols are isomerized by catalytic amounts of this Pd(II) complex to 8,e-unsaturated ketones with a stereoselectivity >90%.2... 

The allylic secondary alcohol l,5-hexadiene-3-ol reacts with phosphorus tribromide plus 2 drops of 48% hydrobromic acid to give in high yield a mixture of... 

In the hydrogenation of l,5-hexadiene-3-ol the double bond in the P position with respect to the hydroxy group reacted more rapidly in all solvents, but the differences were again not pronounced. The effect of solvents on the selectivity of hydrogenation of l,5-hexadiene-3-ol was small. 

The most marked effect of solvents was observed on the rate constants of reactions by which l,5-hexadiene-3-ol is consumed, and on the adsorption coefficients of both alcohols related to l,5-hexadiene-3-ol. In solvents with preferential adsorption of l,5-hexadiene-3-ol (methanol, ethyl acetate, 1,4-dioxane) the rate constants had the lowest values. Such an interesting compensation of the kinetic and adsorption terms has also been observed in other cases (77). Correlations between the relative adsorption coefficients and the parameters (p satisfied Eq. (23) with the absolute term q [similarly to Eq. (22)], the physical meaning of which remains obscure. Correlation analysis confirmed the more general character of the parameter compared with the parameter t. ... 

Compounds containing a l,5-hexadien-3-ol system undergo anionic oxy-Cope rearrangement when treated with the phosphazene superbase Bu-P4. The sigmatropic rearrangement occurs in hexane as well as in THF. The weaker phophazene base Et-P2 failed to induce rearrangement. This is the first example of the use of a metal-free base to induce anionic oxy-Cope rearrangement [49] (Scheme 5.30). 

Evans et al. have observed dramatic rate enhancements in the thermal rearrangements of the potassium or sodium salts of l,5-hexadiene-3-ols. DME is generally superior to THF as solvent. 

Beside the reactions which he directly studied, Dreyfuss also compared the effectiveness of the two different reaction procedures, i.e. the one-step Barbier reaction and the two-step method via the Gilman-McGlumphy reagent, for the synthesis of l,5-hexadien-3-ol. 

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