10, It is but slightly volatile with steam ane has a distinct, sweet adore reminiscent 
salicylaldehyde and (less) of vanillin. Its phenylhydrazone melts at about 143°, its 
micarbazone at- about 133°, both compounds being difficult to purify. The ethyl- 
is formed, m.p. 55.5 to 56.2° (Nomura: 55 to 56°). At any rate, both preparations of 
n their melting points. By oxidizing methylzingerone with sodium hyperbromite, Lapworth 
and his collaborators obtained the same 6-3, 4- -dimethoxyphenylpropionic acid as Nomura. 
A synthesis of zingerone, methylzingerone, and some acids connected with these 
Bhadics has been described by A. Lapworth and F. H. Wykes*). They prepared _ from 
= vanilline and acetoacetic ester vanillylidene acetoacetic ester (VI) according to- the 
it directions given by E. Knoevenagel and F. Albrecht’), dissolved the ester in dilute soda 
"solution and’ reduced it to vanillyl acetoacetic ester by means of sodium amalgam. 
2 soda they obtained vanillyl acetoacetic acid (VIII) which on heating in vacuo split off 
carbon. dioxide with formation of a mixture ofa phenol and an acid. On. treatment 
proved to be identical with the zingerone chlorocarboxylic ester mentioned before. 
When “saponified, .the ester yielded free zingerone, m.p. 36 to 379, ie 
__Styrylmethylketone (X) and the latter reduced, in alcoholic. solution, by means of sodium 
an nalgam to 3 , 4-dimethoxyphenylethy! methyl ketone, or zingerone methyl ether. The 
3 ett ler thus produced was identical with the ether. prepared from natural zingerone. 
Ee im It is not impossible that zingerone is identical with “paradol” isolated by Thresh’*) 
= nis investigations on hearing of Lapworth’s succeSsful synthesis of zingerone. Whereas 
ne arly unaffected in the case of paradol. From, gingerol, Nelson obtained a Solid 
methyl ether, m. “Py 65 to 65.59; paradol yielded the same ether. 
* 
= | OCH, ~ be hy! OCH, 
“en.con(cH.coVe He¢ oH ? (GeHsCO(CH,CO)CH: mc¢ DoH 
(V1) Vaniiyhidene acetoacetic ester. | eo EVID) Vanilly! acetoacetic ester. 
OCHs; 
(HO;C)(CHCO)HC- sera Pees 
vm) Vanilly! acetoacetic acid. 
ee: OCH; | OCH; 
me oncé och, A CH, COCH, | > CH,COCH: CH ~Nocn, 
- : Acetone. <i a. 
bs (UX) Veratric BAVA, Maa Tae / (x) 3, £Dimethoxystyry methyl ketone. 
Mee Journ. chem. Soc. 111 (1917), 690, = 2) Berichte 37 mene 4476. me loc. cit. — 6) Journ. Americ. 
. Soc. 39 (1917), 1466. 
or noes 0 ove ESSENTIAL ots. ee id a a: a | 
bonate melts at 45 to 47°. ‘On methylation with methyl sulphate, methylzingerone _ 
“fingerone (of Lapworth and of Nomura) are identical, without regard to the difference | : 
sy saponifying the reaction product (filtered off from the mercury) with hot caustic : 
of the former with ‘chlorocarboxylic ester a body of ‘the m. p. 47.5° resulted, which — 
The synthesis, of zingerone methyl, ether was achieved. by Lapworth and Wakes ag! 
F follows: — veratric aldehyde (LX) and acetone were condensed to form 3,4-dimethoxy- — 
fr rom grains of paradise. E. K. Nelson’), however, has found differences, yet he stopped 
“the pungent taste of gingerol disappears on boiling | with alcoholic potash, it remains 
