— iig — 



ary menthol which is now also produced by synthesis. With carbanil 

 it forms no urethane, but loses readily thereby water, and yields an 

 inactive menthene. Schindelmeiser has recently examined tertiary 

 menthol more closely in Kondakow's laboratory, and has found that 

 it behaves like Baer's alcohol. The menthene formed in the same 

 manner has the following constants: boiling point 170 to 1 75 °; 

 d^- 0,812; n D20 o 1,45627; «d + o°. It forms a liquid nitroso- 

 chloride which passes over undecomposed with water vapour, which 

 does not readily split off hydrochloric acid with sodium alcoholate or 

 alcoholic potash, and consequently does not readily yield nitrosomenthene. 

 The nitrosochloride boils at 128 to 140° (11 mm. pressure), and is 

 inactive. The solid nitrosochloride from Kremers' menthol cannot 

 be driven over with water vapour without decomposition. Kondakow 

 has obtained another inactive menthol, different from Baer's, when 

 reducing diosphenol; boiling point 214,5 to 216 (atmospheric pressure), 

 98 to 1 00,5 ° (12 mm. pressure), d«2oo 0,9052, n D 1,464456, molecular 

 refraction 47,59. ^ congeals on cooling, and with suitable treatment 

 yields an inactive menthene of the following properties; boiling point 

 168 to 169 °, d-^- 0,8264, molecular refraction 45,73. This menthol 

 greatly resembles Brunei's 1 ) a-thymomenthol, for which the follow- 

 ing constants are given: boiling point 215,5°; °V 0,913; melting point 

 — 5°. The corresponding menthene boils at 167 to 16 8°, d^o 0,823. 

 But whether these two menthols are identical must remain for the 

 present an open question. 



With regard to the examination of the oil of buchu leaves, 

 Kondakow states further that dipentene and limonene are present 

 in it. The ketone to which reference has already been made, boils 

 at 86° (10 mm. pressure); «d — 51°. It forms a liquid oxime and 

 a hydrazone of the melting point 8o°, further two semicarbazones 

 with the melting points 180 and 123°. From the former is regenerated 

 by means of sulphuric acid a strongly inverted ketone with the following 

 physical constants: boiling point 85,5 to 86° (10 mm. pressure), 

 °49,5 o0 >897, Md — 22,3°, rip 1,45169, molecular refraction 46,28. 



Tertiary menthol, and from it an inactive menthene, have been 

 produced by W. H. Perkin jun. 2 ) by synthesis in the following 

 manner: a-Bromohexahydro-p-toluylic acid, formed from hexahydro-p- 

 toluylic acid on treatment with phosphorus pentachloride and bromine, 

 yields on hydrolysis with dilute soda solution, in addition to Z^-tetra- 

 hydro-p-toluylic acid, a-hydroxyhexahydro-p-toluylic acid of the melting 



2 ) Bull. Soc. Chim. III. 33 (1905), 569; Report April 1905, 103. 

 2 ) Proceed. Chem. Soc. 21 (1905), 255. 



