Notes on scientific research. 105 



When sodium hydroxide acts on n-butyl alcohol, some 80 per cent, of sodium 

 butyrate are the chief product; further, with a great excess of butyl alcohol, small 

 quantities of a-ethylhexyl alcohol and a-ethylhexoic acid. Ethyl alcohol, on the other 

 side, yielded under the same considitions only small quantities of acetic acid. Metallic 

 calcium had a similar effect on n-butyl alcohol as sodium, but the yield of «-ethylhexyl 

 alcohol was small and that of n-butyric acid was minimal. 



By means of sodium there were obtained, from a mixture of n-butyl alcohol and 

 ethyl alcohol, as chief products, a-ethylhexyl alcohol and hexoic acid, further n-butyric 

 acid and very little n-hexyl alcohol, acetic acid and a-ethylhexoic acid. Passed over 

 aluminium oxide at 380 to 400 Q , a-ethylhexyl alcohol yielded quickly octylene (b. p. 121°) 

 which, when shaken with 80 per cent, sulphuric acid, was a polymerised into a hydro- 

 carbon (C 8 Hi 4 )n of pleasant odour, probably dioctylene (b. p. 245 to 250°). 



Treated with 10 per cent, potassium hydroxide n-butyl aldehyde and acetone 

 were condensed into an aldol which on distillation yielded n-butylidene acetone 

 CH 3 CH 2 CH 2 CH : CHCOCH3, a colourless liquid turning quickly yellow on exposure to 

 air (b. p. 157°, semicarbazone m. p. 118°). When butylidene acetone was passed over 

 reduced copper oxide at a temperature of 700 to 800°, a small quantity of toluene 

 and a phenolic body, probably cresol, were produced. 



When w-butyl alcohol and acetone were passed over aluminium oxide at 300 to 

 350°, several products could be isolated: — methylamyl ketone (b. p. 148 to 150°), a 

 heptadiene C 7 H 12 (b. p. 94 to 96°), further an unsaturated alcohol, probably an isomeride 

 of amyl ketone, and substances which boiled between 70 and 80° (13 mm.) and between 

 100 and 110° (13 mm.), in addition to traces of n-butyl aldehyde and isopropyl alcohol. The 

 mixture of ??-butyl aldehyde and acetone, passed in molecular proportions over aluminium 

 oxide at 300 to 350°, yielded in the first instance butylidene acetone which, on dehydration, 

 gave two hydrocarbons C7H10, probably of the formula? CH 3 CH 2 CH 2 CH : C : C : CH 2 (?) 

 (b. p. 60 to 70°), and CH 3 CH 2 CH 2 CH : CHC:CH (b. p. approx. 100°). 



Pulegol. — By the reduction of pulegone in alcoholic solution with the calculated 

 amount of metallic sodium Tiemann and Schmidt 1 ) had obtained a pulegol which was 

 not free of menthol. In order to prepare pure pulegol, which had not yet been iso- 

 lated, V. Paolini 2 ) resumed the work of Tiemann and reduced pure pulegone (b. p. 221 

 to 222°; [«] D + 22.85°) by means of sodium in alcoholic solution. He obtained a 

 product which left in the steam distillation a yellow resinous residue (30 per cent), 

 the part distilled (70 per cent.) being of alcoholic character. The residue seemed to 

 be identical with the bis-pulegone C 20 H 3 4O 2 which Harries and Roeder 3 ) had obtained 

 in the reduction of pulegone by means of aluminium amalgam; the constitution of 

 this body is not quite settled, however. Probably a mixture of optical isomerides was 

 being dealt with. 



From the distillate Paolini was able to isolate — by means of the acid phthalic 

 esters, both by the method used 4 ) in the pure preparation of the isomeric thujyl alcohols 

 and with the aid of the strychnine compounds — /-menthol (m. p. 44°; b. p. 214° [corr.]; 

 Md — 49.10°); (Z-menthol (m. p. 88 to 89°; b. p. 214°; [a] D — 21.8°); and Z-pulegol 

 (m. p. 44 to 47°; [«] D — 54.6°). The intermediate products, prepared and partly 

 identified by elementary analysis, were: — the strychnine salt of the phthalic acid- 

 Z-monomenthylester (m. p. 157 to 158°; [a] D — 44.46°); the strychnine salt of the 



*) Berl. Beriehie 29 (1896), 914. — 2 ) Rend, della R. Accademia del Lincei, Roma 28 (1919), II. 190. Reprint 

 was kindly sent to us. — 3 ) Berl. Berichte 32 (1899), 3367. — *) Cf. Report October 1911, 142. 



