781 LXIII.-Tlle Rotatory Power of Benzene-derivatives. By J. LEWKOWITSCH Ph.D. THE concluding remarks in the paper of F. Herrmann (Berichte 21, 1959) refer t o a subject on which I have been making a few experi-ments. In one of my papers (ibid. 16 1576) I mentioned that if benzene be represented by Ladenburg’s prism symbol an asymmetric carbon-atom may be contained in a tri-derivative in which there are three dissimilar radicles the position of which represented by means of the conventional simple hexagon symbol are 1 2 3 the asym-metric carbon-a#tom being that in the position 5 . Although it is vcry unlikely indeed that such substances would be possessed of rotatory power it is conceivable that they might be resolved into two substances of opposite rotatory power just as 1 succeeded in splitting mandelic acid into two optically active isomer-ides (ibid.16 2721). Through the kindness of Professor 0. Jacobsen I was enabled to examine four benzene-derivatives which seemed to be suitable for my purpose viz. :-1 2 3 /?-Metahoillosalicylic acid CsH,(CH3) (COOH) (OH) .* p-Orthohomometahydroxybenzoic acid C,H,( OH)(CH,) (COOH * Methoxytoluic acid C6H3(OCH3) (CH3) (COOH).t a-Nitro-orthotoluic acid CsH3(N02) (CH,) (COOH).f When examined by the polnriscope they did not exhibit any rotatory power. I tried to split the first three by converting them into their cinchonine salts (comp. malic acid mandelic acid). The cinchonine salts crystallised rery well indeed but the acids thrown down by ammonia from their solutions were optically inactive. The method of splitting by allowing fungi to grow in a solution containing the snbstances to be examined could only be tried with the fourth sub-stance as mere inspection of the formulze would indicate ; but even this substance has such strong antiseptic properties that Penicilliurn glaucwnz did not thrice in its solution. t ibid. 16 1964 1 2 3 1 2 3 I 2 3 J Ber. 16 1963. $ ibid. 16 1958