390 SCIENCE PROGRESS 



succinic dialdehyde, methylamine and acetone, and the author 

 has now found that tropinone could actually be obtained in 

 small yield by the condensation of these three substances in 

 aqueous solution. A better yield, however, amounting to 

 42 per cent, of the theoretically possible, was obtained by 

 replacing the acetone by the calcium salt of acetone dicarboxylic 

 acid and allowing the condensation to proceed in aqueous 

 solution for about fifty hours according to the following scheme : 



CHO CH 2 .COO, CH — 



/ \ / 



CH 2 \ CH 2 



I +NH 2 CH 3 + CO >Ca= I NCH 3 CO 



CH 2 / CH 2 



CHO CHo.COO/ CH CH 2 COO 



11 



The resulting calcium tropinone dicarboxylate II. loses two 

 molecules of carbon dioxide when acidified and heated, yielding 

 tropinone I. It is hoped to improve the conditions of this 

 synthesis, so as to make tropinone an easily accessible substance 

 and thereby to render the technical preparation of homatropine 

 and tropacocaine feasible and also to bring within the range 

 of possibility the technical synthesis of atropine. The author 

 has found a convenient method of identifying small quantities 

 of tropinone depending on the formation of a characteristic 

 crystalline derivative by condensation with piperonal in aqueous 

 alcoholic solution. 



In a subsequent paper, entitled " A Theory of the Mechanism 

 of the Phytochemical Synthesis of Certain Alkaloids " (/. Chem. 

 Soc. 191 7, 876), the same author elaborates the above synthesis 

 of Tropinone with a view to offering a possible explanation of 

 the formation of most of the important alkaloids within the 

 plant. It is pointed out that most of the laboratory syntheses 

 of alkaloids involve experimental conditions differing entirely 

 from those obtaining in a plant, or, on the other hand, it has 

 frequently been assumed that plants have at their disposal 

 enormously powerful reagents which are able to bring about 

 reactions which cannot be reproduced in the laboratory, whereas 

 in the author's opinion insufficient attention has so far been paid 

 to the possibility of the formation of highly reactive inter- 

 mediate products which can undergo a number of comparatively 



