124 REPORT— 1902. 



Homologues have been obtained from substituted ketohexahydrobeu- 

 zeues (p. 126) by reduction ' or by the action of magnesium and alky] 

 iodides ;2 also from ketotetrahydrobenzenes (p. 128) by the action of sodium 

 in alcoholic solution : — ^ 



.CH„ . CO XHj . CHOH 



CH, \CH CH„ \CH., 



^CH„ . C . CH, \CH„ . CH . CH . CH, 



1 : Ai-Dihydroxyhexahydrobenzene (quinite) 



yCHo . CHg 



HO . CH \CH . OH 



\CH„ . CH., 



the simplest member of the inosite series is produced by the reduction of 

 diketohexahydrobenzene (p. 128). It is a solid which tastes sweet at 

 first, then bitter, and on oxidation with chromic acid is converted into 

 quinone.* Homologues can be obtained in an analogous manner from 

 substituted diketohexahydrobenzenes.'' 



Substituted 1 : 3-dihydroxyhexahydrobenzenes result from the reduction 

 of substituted dihydroresorcins ; •" 1 : 2-dihydroxyhexahydrohenzene ; '' 

 1 r 3 : b-trihydroxyhexahydrohenzene (phloroglucite).** 



In this group must also be included quercite and inosite, formerly 

 classed with the sugars. 



Pentahydroxyhexahydrohenzene (quercite) occurs in acorns, the aqueous 

 extract of which can be freed from glucose by fermentation, leaving 

 quercite unaltered. The pure substance crystallises in monoclinic prisms, 

 melting at about 225°, and is optically active [a]o = + 24°-24. It yields 

 many well-characterised compounds, among which may be mentioned the 

 pentanitrate and pentacetate. The following formula 



.CH(OH) . CH . OH 



CHj \CH . OH 



\CH(0H) . UH . OH 



was suggested by Kannonikow after Prunier ^ had shown that hydriodic 

 acid converts quercite into benzene, phenol, iodophenol, quinone, and 

 hydroquinone, and fusion with potash gives rise to hydroquinone and 

 pyrogallol. Kiliani and Scheibler '" doubted this formula, as they could 

 only obtain mucic and trihydroxyglutaric acids by oxidising quercite with 

 nitric acid ; but in 1896 Kiliani and Schafer ^^ showed that potassium 

 permanganate oxidises quercite to oxalic and chiefly malonic acids, thus 

 proving the pi-esence of a methylene group, which fact, in conjunction 

 with the above data, definitely proves Kannonikow's formula to be the 

 true one. 



Hexahydroxyhexahydrobenzene (inosite) is known in one inactive and 



'- Zelinsky, references, p. 7. = Zelinsky, Ber., 1901, 34, 2877. 



» Knoevenagel, Annalen, 1896, 289, 131 ; and 1897, 297, 113. 



* Baeyer, Ber., 1892, 25, 1037. 



* Baeyer, ibid., 2122; and 1893, 26, 232. 



« Knoevenagel, Amialen, 1896, 289, 187. ' Annalen, 1898, 302, 21. 



" Wislicenus, Ber., 1894, 27, 357. " Ann. Cldm. Phys., 1879 [5], 15, 1. 



'» Ber., 1889, 22, 517. " Ber., 29. 1762. 



