Methyl pentane diol

Solvent-soluble polymeric products of stmctures (1 3) can be obtained upon reaction of tetraaLkyl titanate, 2-methyl- -pentane-2,4-diol, and water in a 2 4 1 molar ratio (71). The tetraptimary glycol titanate complexes have been used as catalysts for the production of polyisocyanurates and polyoxa2ohdones (72). 

Aznarez et al. [2] have described a Spectrophotometric method using curcumin as chromopore for the determination of boron in soil. Boron is extracted from the soil into methyl isobutyl ketone with 2-methylpentane-2,4-diol. In this method 0.2-lg of finely ground soil is digested with 5ml concentrated nitric-perchloric acid (3 + 1) in a polytetrafluoroethylene lined pressure pump for 2h at 150°C. The filtrate is neutralized with 6M sodium hydroxide and diluted to 100ml with hydrochloric acid 1+l.This solution is triple extracted with 10ml of methyl isobutyl ketone to remove iron interference. This solution is then extracted with 10ml 2-methyl pentane-2,4 diol and this extract dried over anhydrous sodium sulphate. 

The result of the retrosynthetic analysis of rac-lO is 2-hydroxyphenazine (9) and the terpenoid unit rac-23, which may be linked by ether formation [29]. The rac-23 component can be dissected into the alkyl halide rac-24 and the (E)-vinyl halide 25. A Pd(0)-catalyzed sp -sp coupling reaction is meant to ensure both the reaction of rac-24 and 25 and the ( )-geometry of the C-6, C-7 double bond. Following Negishi, 25 is accessible via carboalumination from alkyne 27, which might be traced back to (E,E)-farnesyl acetone (28). The idea was to produce 9 in accordance with one of the methods reported in the literature, and to obtain rac-24 in a few steps from symmetrical 3-methyl-pentane-1,5-diol (26) by selective functionalization of either of the two hydroxyl groups. 

The preparation of vinyl iodide 39 first required the transformation of (E,E)-farnesyl acetone (28), performed according to Negishi, to the terminal alkyne 27 with 75% yield [35]. The latter then gave (E)-vinyl iodide 39 in dia-stereomerically pure form and 74% yield by Zr-catalyzed carboalumination with trimethylaluminum and trapping of the intermediate vinylaluminum species with iodine [36]. The alkyl iodide rac-29 necessary to ensure the coupling with 39 was obtained by selective monofunctionalization of 3-methyl-pentane-1,5-diol (26) in a few steps [37]. 

As mentioned above, the advantage of the prochiral 3-methyl-pentane-1,5-diol (26) is that we should be able to derive the two enantiomers (R)-29 and (S)-29 necessary for the synthesis of methanophenazine (10) in enantiomerically pure form by differentiating its enantiotopic (CH2)20H groups [40]. 

Some solvents are reluctant to crystallize before turning into a glass, including allyl alcohol (2-propen-l-ol), ethylene glycol (1,2-ethanediol), and hexylene glycol (2-methyl-pentane-2,4-diol). Some common solvents may be liquid below their freezing points if they contain impurities, in particular small amounts of water. Thus, /-butyl alcohol (2-methyl-2-propanol), acetic acid, and phenol can appear liquid at or below ambient temperatures (i.e., < Tm) due to this cause. 

Kuraray An intermediate for 3-methyl 1,5-pentane diol Rh4(CO)12 with phosphorus ligand as the precatalyst hydroformylation of 2-methyl buten-4-ol followed by hydrogenation Reaction 5.10... 

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... 

METHYLPENTANE see MNI500 2-METHYL PENTANE-2,4-DIOL see HFP875 2-METHYL-2,4-PENTANEDIOL see HFP875 2-METHYLPENTANOL-l see AOK750 2-METHYL-4-PENTANOL see MKW 600... 

The first crystals of ascorbate oxidase were grown by Ladenstein et al. (85) in a final 1.2 M sodium-potassium phosphate buffer, pH 7.0. They were orthorhombic, space group P2i2,2i with a = 190.7 k, b = 125.2 A,c = 112.3 A, and two molecules (four subunits) per asymmetric unit. Some years later Bolognesi et al. (86) obtained a different crystal form of ascorbate oxidase with 2-methyl-2,4-pentane-diol as precipitant. The crystals were orthorhombic as well, space group P2j2j2 with a = 106.7 A, b = 105.1 A, c = 113.5 A, and one molecule (two subunits) per asymmetric unit. In both cases, the protein material was prepared from the peels of green zucchini squash (C.pepo medullosa). The preliminary three-dimensional X-ray structure of ascorbate oxidse, based on... 

Meprobamate has been synthesized by several procedures (See Figure U). The first step is to synthesize 2-methyl-2-propyl-1,3-propanediol. This has been done1 1 by reacting 2-methyl pentanal and formaldehyde in presence of KOH. The diol has also been prepared by reducing 2-methyl-2-n-propyl malonic acid, diethyl ester with lithium aluminum... 

Oxidation of Prochiral Diol. The oxidation of prochiral diol 3-methyl-1,5-pentanediol did not give the corresponding -hydroxy aldehyde but gave the corresponding lactol at 22% yield. To determine stereochemistry of the lactol, this was chemically oxidized by Ag20 and afforded 3-(R)-methyl-pentan-l,5-olide at 38% optical purity. (Figure 9). This was determined by comparison of optical rotation with a reference (70). 

In the chiral molecule 2,2,4-trimethyl-l,3-pentane-diol (Fig. 5.4), we note that CH3a and CH3b are not equivalent, and two peaks are seen. Even though the two methyl groups labeled c are not equivalent, they coincidently show only one peak. Two peaks may be seen at higher resolution. 

Synonyms/Trade Names 2,4-Dihydroxy-2-methylpentane 2-Methyl-2,4-pentanediol 4-Methyl-2,4-pentanediol 2-Methyl pentane-2,4-diol ... 

Recently important results were obtained using catalysts supported on chiral natural materials containing pol5 eptides and polysaccharides. According to Yin et al. a wool-Pd complex at 30°C and 1 bar hydrogen was found to catalyze the as5mimetric hydrogenation of 4-hydroxy-4-methyl-pentan-2-on (diacetone alcohol), I, into (R)-2-melhylpentane-2,4-diol, 2 with an ee of 73% and 3-methylbutan-2-one, 3 into (i )-3-methylbutan-2-ol, 4, with an ee of 100% (Scheme 5.4.). 

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