APPENDIX 



283 



To be added to synthetical pro- 

 cesses : 



[D, p. 91.] From methyl and ethyl 

 alcohols [13 ; 14], glycerol [48], potas- 

 sium cyanide [172], and acetic acid 

 [Vol. II]. Ethyl chloracetate is con- 

 verted into ethyl cyanacetate by inter- 

 action with potassium cyanide and 

 glycerol into /3-iodopropionic acid and 

 ester (see under resorcinol [70 ; 3?, 

 p. 1 14] and, for preparation of /3-iodo- 

 propionic ester, also "W. H. Perkin, 

 junr., Trans. Ch. Soc. 85, 422, note). 

 Cyanacetic and /3-iodopropionic esters 

 condense under the influence of sodium 

 ethoxide to form ethyl y-cyanopentane- 

 aye-tricarboxylate : the latter on hydro- 

 lysis by hydrochloric acid yields pent- 

 ane-aye-tricarboxylic acid (Ibid. 422). 

 The tricarboxylic acid when digested 

 with acetic anhydride gives 8-keto- 

 hexahydrobenzoic acid, the ester of 

 which interacts with magnesium meth- 

 iodide to form among other products 

 cis - 8 - hydroxyhexahydro - p - toluic acid 

 (W. H. P., junr., Proc. Ch. Soc. 20, 

 86 : see also Stephan and Helle, Ber. 

 35, 2153). The latter acid (or its 

 lactone formed by the action of heat) 

 combines with hydrogen bromide to 

 form 8-bromhexahydro-p-toluic acid, 

 and this on debromination by the 

 action of pyridine or sodium carbonate 

 is converted into A 3 -tetrahydro-p-toluic 

 acid, the ester of which interacts in 

 ethereal solution with magnesium meth- 

 iodide to form a product which yields 

 inactive terpineol on decomposition by 

 hydrochloric acid (W. H. P., junr., 

 loc. cit.]. 



NOTE : Succinic acid is also a generator of 

 /3-iodopropionic acid (see under resorcinol [70 ; 

 F, p. 145]). Cyanacetic acid is also obtainable 

 from oxalacetic ester (see under n-propyl 

 alcohol [15 ; Z, p. 63]). 



stituent of the oil of Calif ornian laurel 

 from Umlellularia californica (Power 

 and Lees, Proc. Ch. Soc. 20, 88). 



41. Menthol (p. 93). 



For variation in composition of 

 peppermint oil from Mentha piperita 

 according to climate, cultivation, &c., 

 see Charabot and Hebert, Ann. Agro- 

 nom. 28, 595. For quantities of 

 menthol in Italian peppermint oils see 

 Zay, Staz. sper. agrar. 35, 816; Ch. 

 Centr. 1903, 1, 331. 



To be added to synthetical pro- 

 cesses : 



[B, p. 93.] For reduction of menth- 

 one to menthol see further Beckmann's 

 Germ. Pat. 42458 of 1887; Ber. 21, 

 Eef. 321. 



42. Isopulegol (p. 93). 



The relationship of this compound 

 to d-citronellal [105] and the modifica- 

 tion of the formula of the latter (see 

 this appendix under citronellol [38, 

 above]) makes the formula of iso- 

 pulegol : 



CH 3 



CH 



CH 2 

 H.C CH(OH) 



CH 

 H,C.C:CH 2 



For transformation of d-citronellal into 

 isopulegol by the action of dilute sul- 

 phuric acid see Barbier and Leser, Comp. 

 Rend. 124, 1309. 



4O. Cineole (p. 91). 



Cineole (eucalyptole) is always present 

 in peppermint oil from Mentha piperita 

 (Charabot and Hebert, Ann. Agronom. 

 28 > 595)- The presence of cineole in 

 lavender oil has been confirmed (Schim- 

 mePs Ber. April, 1903; Ch. Centr. 

 1903, 1, 1086). Cineole is 



a con- 



44. Methylacetyl Carbinol (p. 94). 



To be added to synthetical pro- 

 cesses : 



[D, p. 94, note.] Magnesium ethiodide or 

 bromide and acetamide interact to form a com- 

 pound which on decomposition by water yields 

 methyl ethyl ketone (Beis, Comp. Rend. 137, 



575)- 



