H2C  CH—CH2 H2C•CH—CH2 H2C•CH•CH2•CO2H H2C•CH—CH2 N°Me CHOH NN/1e CO NI N Me NMe CIH I ~I II HZC•CH—CHI 2 HZC•CHI —CHI 2 HZC•CI H•COZH HZ •CH—CH

Tropine Tropinone Tropinic acid Tropidine . On the synthesis of tropine, see R . Willstatter, Ber., 1901, 34, pp . 130, 16 Tropic acid, C9H1003, the other decomposition product of atropine, is a saturated hydroxy-acid which is readily converted into atropic acid, C9H802, by dehydrating agents . This latter acid is shown by all its reactions to be C6H5C(:CH2)•CO2H, a fact which is confirmed by its synthesis from acetophenone by the action of phosphorus pentachloride, followed by the decomposition of the resulting chloride with an alcoholic solution of potassium cyanide and subsequent hydrolysis of the nitrile so formed . These results show that tropic acid must be either C6H5•CH(CH2OH)•CO2H or C6II5C•(OH)(CH3)•CO2H, and since the latter compound has been prepared from acetophenone by the addition of the elements of hydrocyanic acid, followed by subsequent hydrolysis and is an isomer of tropic acid, it follows that tropic acid must be represented by the former of the two formulae . Hence the alkaloid atropine, being a tropine-tropate, must have the annexed formula H2C•CH—CH2 CH2OH NMe CI H•O•CO•CH I 1 H2C•CI H--CH2 C6H5 Atropine .