3-Methyl-1,6-hexanediol

A series of cholesteric polyesters were also prepared in our laboratory from either (+) 3-methyladipic acid ot (+) 3-methyl-1,6-hexanediol with the following structures ... 

The formation of a chiral center on addition of a substituent to a flexible fr agment and the cholestmc polymo and chiral polymeric smectics that result are of qiecial interest Optically active (+)3-methyladipic acid in association with 1,4-dioxy-a-methylstilbaie [33], an q)tically active (+) isomer of 3-methyl-1,6-hexanediol [34], was used as the monomer for these purposes. The most... 

Copolymer of p-hydroxybenzoic acid and 3-methyl- 1,6-hexanediol-terephthalic acid Single microscopy Transition temperature from a mesophase to an isotopic phase changed continously and smoothly depending on the composition 380... 

A chain extender could be selected from the following compounds ethylene glycol, 1,2-propanediol, 1,4-butanediol, 1,3-butanediol, neopentanediol, hexanediol, methyl-dihydroxylethyl amine (MDEA) [9], etc. These should be as dry as possible. 

Abou-Donia MB, Makkawy HA, Graham DG. 1982. The relative neurotoxicities of -hexane, methyl n-butyl ketone, 2,5-hexanediol, and 2,5-hexanedione following oral or intraperitoneal administration in hens. Toxicol Appl Pharmacol 62(3) 369-389. 

It not tertiary, the product yield is lowered by transfer of the carbinol hydride ion to the aldehyde to produce a new alkoxide and an enolate ion. Thus, propylene oxide, after reductive cleavage with LDBB and trapping with isobutyraldehyde or p-anisaldehyde, provided 5-methyl-2,4-hexanediol in 40-50% yield or 1-p-anisyl-1,3-butanediol in 44% yield, respectively (in both cases about equal mixtures of diastereoisomers were obtained). The cyclohexene oxide-derived dianion, when trapped with isobutyraldehyde, gave 2-(1-hydroxy-2-methylpropyl)cyclohexanol in 71% yield as a mixture of only partially separable isomers in the ratio 15 11 39 35. 

Oxidation of -hexane with Co AlPO-18 with 10% rather than 4% of the framework AP ions replaced with Co resulted in a dramatic enhancement in the formation of adipic acid [65]. It was argued that in these catalysts two Co ions are ideally separated by 7-8 A on the inner wall of the zeolite, allowing both methyl groups unfettered access to catalytically active sites. Furthermore, it was demonstrated that 1,6-hexanediol and 1,6-hexanedial served as precursors to the adipic acid. On the other hand, 1-hexanol, hexanoic acid, and hexanal, which were also formed in the reaction, did not serve as precursors for the adipic acid. It is tempting to suggest that the mono-oxidized hexane products were produced in regions of the zeolite where simultaneous access to two catalytically active sites was not possible. 

Eben A, Flucke W, Mihail F, et al. 1979. Toxicological and metabolic studies of methyl n -butylketone, 2,5-hexanedione, and 2,5-hexanediol in male rats. Ecotoxicol Environ Safety 3 204-217. 

Makkawy HM, Graham DG, Abou-Donia MB. 1981. Differential neuro toxicity ofn-hexane methyl-n -butyl ketone, 2,5-hexanediol and 2,5-hexanedione following subchronic 90 days oral administration in hens. Fed Proc 40 678. 

A new enantiopure, bidentate ligand (35, 45 )-2,2,5,5-tetramethyl-3,4-hexanediol [(35, 45)-186] was developed by Yamanoi and Imamoto and investigated as asymmetric inductor in the titanium-catalyzed sulfoxidation reaction with various hydroperoxides as oxygen donors (Scheme 107). The catalytically active species was then prepared in situ from Ti(OPr-/)4 and ligand (35,45)-186. The most efficient hydroperoxide in terms of enantio-selectivity turned out to be cumyl hydroperoxide (95% ee compared to 30% ee in the case of methyl p-tolyl hydroperoxide), and molecular sieves 4 A had a beneficial effect on the... 

Following route A (Fig. 1), Yan Xiao et al. reported the chemoenzymatic synthesis of poly(8-caprolactone) (PCL) and chiral poly(4-methyl-8-caprolactone) (PMCL) microparticles [5]. The telechelic polymer diol precursors were obtained by enzymatic polymerization of the corresponding monomers in the presence of hexanediol. Enzymatic kinetic resolution polymerization directly yielded the (R)-and (S )-enriched chiral polymers. After acrylation using acryloylchloride, the chiral and nonchiral particles were obtained by crosslinking in an oil-in-water emulsion photopolymerization. Preliminary degradation experiments showed that the stereoselectivity of CALB is retained in the degradation of the chiral microparticles (Fig. 2). 

A plausible mechanism involves the reaction of the dihydride precursor with t-butylethylene to the 14-e complex [Ir(C6H3-2,6 CH2P-f-Bu2 2)]> which undergoes the oxidative-addition reaction of the alcohol to afford a hydride alkoxide complex. Further /i-hydride ehmination gives the alde-hyde/ketone and regenerates the dihydride active species [55]. In the particular case of 2,5-hexanediol as the substrate, the product is the cycHc ketone 3-methyl-2-cyclopenten-l-one. The formation of this ketone involves the oxidation of both OH groups to 2,5-hexanedione followed by an internal aldol reaction and further oxidation as in the final step of a Robinson annotation reaction [56]. 

S-Dinitro-2,5-di methyl ol-l, 1 -hexanediol Tetranitrate 2,5-Bis(hydroxymethyl)-2,5-dinitro-l,6-hexanedial Tetranitrate or 1,4 Dinitro-l,l,4,4-tetramethylolbutane Tetranitrate (called by Blatt, Ref 3)... 

Enantiopure 2,2,5,5-tetramethyl-3,4-hexanediol was prepared by Yamanoi and Imamoto [46]. A combination of Ti(0-i-Pr)4 with this diol (1 2) gives a chiral catalyst for sulfide oxidation with cumyl hydroperoxide in the presence of 4A molecular sieves in toluene. At -20°C p-tolyl methyl sulfoxide (95% ee) was obtained in 42% yield together with 40% sulfone, A kinetic resolution increased, to some extent, the enantiomeric excess of the product, that is, at lower conversion (20% yield) the enantiopurity of the resulting sulfoxide was only 40% ee. This catalytic system is ineffective for the enantioselective oxidation of dialkyl sulfides. 

The second method for liquefaction makes use of solvolysis during the process [8,11]. By using conditions which allow phenolysis of part of the lignin, especially in the presence of an appropriate catalyst, the liquefaction of chemically modified wood into phenols could be accomplished under milder conditions (at 80 C for 30-150 min). Allylated wood, methylated wood, ethylated wood, hydroxyethylated wood, acetylated wood, and others have been found to dissolve in polyhydric alcohols such as 1,6-hexanediol, 1,4-butanediol, 1,2-ethanediol, 1,2,3-propanetriol (glycerin), and bisphenol A using the liquefaction conditions just described. Each of them caused partial alcoholysis of lignin macromolecules [4]. 

A reaction kettle was charged with polyesterdiol (0.5 mol M 1000 daltons prepared from isophthalic acid, adipic acid and hexanediol), polyethylene glycol (0.05 mol Mw= 1500 daltons), and dimethylolpropanoic acid (1.25 mol) dissolved in methyl ethyl ketone. The mixture was heated to 80°C. When the reaction was completed the... 

SYNS 2,4-DIHYDROXY-2-METHYLPENTANE DIOLANE 1,2-HEXANEDIOL ISOL 2-METHYL PENTANE-2,4-DIOL 2-METHYL-2.4-PENTANEDIOL PINAKON a,a,a -TRIMETHYLTRLMETHYLENE GLYCOL... 

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