Synthesis of Some Hexanediols

Abstract

A general method for the preparation of 1,3-, 1,4-, and l,5-hexanecliols is described. The synthesis involves the preparation of a corresponding lcetohesanoate, \\.hich is reducecl to the diol with l i t h i~~m aluminum hydride. Countercurrent distribution was found useful in the p~~rihcation of small amounts of intermediates and end products. 1,2-, 1,6-, a11cl2,5-hesanediols were also prepared by 1;nomn procedures. The infrared spectra of these diols have been recorded and their p-nitrobcnzoates were prepared.The analysis of mixtures of polyols obtained in the hyclrogenolysis of methyl glucoside (1) required small amounts of various hexanediols for identification purposes. This paper describes a convenient method for preparing 3-, 4-, and 5-ketohe?tanoates, from which the 1,3-, 1,4-, and 1,5-hexanediols were obtained in 75-85% yield by lithium aluminum hydride reduction (2). I t also describes the preparation of 1 3 -, l,6-, and 2,5-hexanediols by known procedures, and the preparation and characteristics of the p-nitrobenzoates. The infrared spectra of all of these hexanediols are recorded.Hexanediols have been prepared by a variety of methods, none of which appeared t o be generally applicable, and inost suffered from the disadvantage that the starting materials were not readily available. Also, different types of crystalline derivatives were reported, malting characterization by comparison difficult. No reference to the iilfrared spectra of these hexailecliols coulcl be found, although Kuhn (3) discusses the effect of hydrogen bonding on the infrared absorptioil band of the hydroxyl groups in 1,G-hexailediol.The direct synthesis of hexanediols by general methods, such as the Grignard synthesis (4), did not appear feasible. A useful approach to their preparation appeared to be the synthesis of the corresponding lteto-or hydroxy-acid (or ester), the latter being reducecl readily to the hexanediol. When the synthesis of 4-and 5-ltetohexanoic acids was attempted on a 10th molar scale by the methods of Winterfeld and Ronsberg ( 5 ) , Yoho and Levine (6), and Perlin and Purves (7) only very low yields of rather impure keto-acids were obtained. Purificatioll by fractional distillation on this scale proved unsatisfactory. The method of Cason et al. (8) for the preparation of keto-esters (111) was then modified according to Perlin and Purves and satisfactory results were obtained when the difficulties of purification of 5 to 1.0 g. reaction products had been overcome. The synthesis involves the preparation of a given carboxy acyl chloride (I), via the semi-ester of the dicarboxylic acid, which was reacted with the appropriate dialltyl cadmium (11). The latter was prepared in isopropyl ether (7) from the Grigllard intermediate.Provided the semi-ester was pure, the lteto-ester was obtained in a satisfactory state of purity on fractional distillation. When the semi-ester was isolated impure (e.g. monoethyl malonate), neither the ketohexanoate nor the hexanediol could be purified satisfactorily 'Manuscript received Novenz...

Evaluation of antifungal and antibacterial activities of monoesters of succinic anhydride

“…All the microbes were found to be sensitive towards compound 20 displaying MIC values 2.12-2.32 µg/mL. The study also showed that halogenated esters (12)(13)(14)(15)(16)(17)(18)(19) (1-8, 21-29) microbes were resistant and showed very small zone of inhibition (Table 1), whereas compounds 9-11 were almost inactive. The prepared compounds showed interesting structure activity relationships while exploring their antifungal and antibacterial activity.…”

“…Relatively high activity was observed for compounds with substituent at 2 and 4 position of benzene ring. Highest activity was revealed by halogenated monoesters (12)(13)(14)(15)(16)(17)(18)(19)(20) in general and iodinated monoesters in particular (18)(19)(20). Monoesters having substituents linked through oxygen to benzene ring (1)(2)(3)(4)(5)(6)(7)(8) and (24-29) displayed relatively less activity as compared to halogenated monoesters.…”

“…Therefore, quite a good number of scientists are involved in the synthesis of biologically active compounds and characterise them with reference to their antimicrobial properties [18][19][20]. In the last report the monoesters of succinic acid (1-29) were synthesised and characterised [19] whereas, in the present study the biological activities of these compounds (1-29) against various microbes are reported.…”

Intramolecular H-transfer reactions during the Decomposition of Alkylhydroperoxides in hydrocarbons as the solvents

“…The diol was purified by distillation (b. p. 105 ' U 0 . 5 kPa [39,401). "C-nnir spectrum see Table 12.…”

“…Commercially available 5-oxocaproic acid ethyl ester (Aldrich) was reduced with LiAlH4 in tetrahydrofurane. The hexane-1,5-diol was purified by distillation (b. p. 109 "C/0.5 kPa [39]). "C-nmr spectrum see Table 12.…”