the still dakiows Hornonivehonic set on eanenine | to homonaranie 
be obtained by condensation with ethyl «-bromoisobutyrate. Now, homofe 
Wissa methylcamphenic acid which when distilling its lead salt should pass 
a-methylcamphenilone, 7.e. fenchone of Semmler’s formula, in the’ same way as lead 
,camphenate yields camphenilone.- Homofenchonic acid was comparatively easy 1 J 
prepare, but the distillation of the lead salt yielded principally a mixture of hydro- 
carbons with inconstant boiling point. — Bee 
Ruzicka was, however, successful in transforming methyl voncaaae! into 2 fenene e 
by methylation. Methyl norcamphor, hitherto unknown, originated? in good yield, fro 1 
methyl norhomocamphoric acid which was obtained by condensing methyl cyclopentanone, 
carboxylate with ethyl bromoacetate. After treating methyl norcamphor twice with sodiun my 
amide and methyliodide, it furnished, in addition to another hitherto unknown int yo 
mediate product, designable as fenchosantenone,- pure r-fenchone. Fenchosantenone a 
could be separated from fenchone on account of its easier formation ofa semicarbazone. 
For the formation of 1- methyl-3-keto- -1- cyclopentane carboxylic acid the author started 
of.the acid in absolute alcohol for 24 Hes with absolute aleahel saturated with hee 
chloric acid gas. When treated with ethyl bromoacetate and zine according to the” 
directions of P. Duden and R. Freydag*), levulic ester furnished a lactonic ester, the. i 
lactone of 2-methyl-2-hydroxyadipic ester (II). This lactonic ester yielded, on heating | 
with potassium cyanide to 240 to 250°, ethyl 2-methyl-2-cyano-1 , 4-butanedicarboxylate (Il). 
This product is heated with alcoholic sulphuric acid for obtaining ethyl 2-meth - : 
1,2,4-butanetricarboxylate (IV). For this purpose, the lactonic ester is heated, w fh 
11/2 mols. potassium cyanide for about 8 hours to 200 to 220° and the product ait this | ie 
reaction boiled for 10 days in an oil-bath heated to 120° with a mixture of concentrated | 
sulphuric acid and alcohol. The tricarboxylic ester (IV) is then boiled in benzene te 
solution with sodium in order to obtain 1-methyl-5-keto-cyclopentane carboxylate. (V); + 
the sodium dissolves rapidly, and the slightly coloured solution is poured, after cooling, 
on ice-water, shaken with dilute sulphuric acid, the solvent removed completely and ; 
residual oil, dissolved in benzene, then boiled with hydrochloric acid of medium) 
concentration. In the beginning, strong evolution of carbon dioxide is noticed. ‘The | 
aqueous solution is extracted with ether. 1-Methyl-3-keto-1-cyclopentane carboxylic acid 
boils at 170° (12 mm.); semicarbazone, m.p. 189 to 190°; ethylate, b.p. 115° (12 mm.) 
By heating the ketonic ester (V), in benzene solution, with ethyl «-bromoisobutyrate 
and zinc, ethyl hydroxyhomofenchonate (VI), b.p. 171 to 173° (12 mm.), is obiatad 
As by-product, dehydrohomofenchonic ester (VII) is formed. an 
‘The hydroxyester, even after repeated heating with potassium hydrogen. sulphate ; 
yields a product of inconstant boiling point; abstraction of water is performed mot 
evenly by treatment with phosphorus tribromide in chloroform solution. The dehyde 
homofenchonic ester thus obtained (VII) boils at #52 to 153° (12 mm.,). , The 
resulting from saponification of the ester is probably a mixture of two acids ot 
m.p. 176 to 177 and 110 to 111°. . 
In consequence of steric hindrance neither the dehydrofenchonic ester nor the 
could be reduced in aqueous-alcoholic or in glacial acetic acid solution by coll 
palladium, under atmospheric pressure, according to Skita. With platinum. bl 
glacial acetic acid (method of Willstatter), however, the hydrogenization was . 
Ethyl homofenchonate (VIII) boiled at 150 to 155° (13 mm.). The free nee mix 
1) Berichte 36 (1903), 953. 
