266 REPORTS o^ the state of science. 



isopropylideneacetoacetate and ethyl sodioacetoacetate, is a 8-ketonic ester 

 with the following constitution ' : — 



CCCHjX, 



HjC 



00 



^\ CH . COOCjH^ 



CH 



C.CH, 



By reduction with sodium and alcohol, a mixture of stereoisomeric 

 hydroxy acids is produced, which does not consist of one cis- and one 

 trans-acid, as stated in the patent, but of three pairs of cis-trans-isomeric 

 acids, in all therefore of six acids, all of which have been isolated. By 

 heating alone or with dehydrating agents three different stable crystalline 

 lactones were obtained, showing that in the parent ketonic acid the 

 carboxyl and carbonyl groups occupy a para-position relatively to one 

 another. A further proof of this is afforded by the fact that the lactones 

 are oxidised by Beckmann's solution to three stereoisomeric dihydroiso- 

 phoroncar boxy lie acids, which distil without decomposition in vacuo, and 

 do not lose carbon dioxide on heating to 200° in air. 



Abati and Bernardinis ^ have isolated two new hydrophthalic 

 anhydrides by the reduction of sodium phthalate with sodium amalgam. 

 Cis-A^-tetrahydrophthalic anhydride crystallises in white scales, and 

 on heating to 220° to 230° is transformed into A^ -tetrahydrophthalic 

 anhydride. 



A^ ■ ^-dihydrophthalic anhydride melts at 58°, and on heating to 225° 

 is transformed into another anhydride, which could not be identified. 



The trans-hexahydroisophthalic acid, previously described ^ as melting 

 at 120° to 122°, has been proved by Perkin and Goodwin ■* to be a mixture 

 of the cis- and trans-acids, which can be separated by dissolving in a 

 considerable excess of ammonia and heating for some hours with calcium 

 chloride, when a quantity of the calcium salt of the cis-acid is obtained. 

 After repeating this process several times, the mother liquor yielded 

 pure trans-hexahydroisophthalic acid melting at 148°. When the pure 

 trans-acid is treated with phosphorus pentachloride and then bromine, 

 1 : 3-dibromo-trans-hexahydroisophthalic acid is produced, which on 

 treatment with methyl alcoholic potash gives a dihydroisophthalic acid, 

 whose constitution is probably represented by the formula 



COOH 



COOH 



It is isomeric with the acid previously obtained from 3 : 4-dibromo- 

 hexahydroisophthalic acid by similar treatment. 



Chlorohexahydrobenzene readily forms a Grignard compound with 

 magnesium,^ which when acted on with dry sulphur dioxide yields 

 magnesium hexahydrobenzenesulphinate. This latter substance on oxida- 



' MerliDg, Ber., 1905, 38, 979. ' J. C. S., Abst.. 1905 (1), 599. 



» J. a S., 1891, 69, 808. * Ibid., 1905, 87, 841. 



« Borsche and Lange, Ber., 1905, 38, 276G. 



