— 88 — 



Umbellulone reacts with semicarbazide and hydroxylamine in pre- 

 cisely analogous manner as certain unsaturated ketones with double- 

 linking in the a , ^-position towards the carbonyl-group do according 

 to the researches by Harries, Tiemann, Rupe and Schlochoff. 

 Its behaviour towards bromine shows further, that only one double- 

 linking occurs in the molecule; for this reason Lees considers um- 

 bellulone an a-/?-unsaturated cyclic ketone with two closed rings. 

 Umbellulone bromide, when heated at reduced pressure, is split up 

 into an unsaturated bromo ketone C 10 H 13 OBr (boiling point 140 to 

 I45°at 20mm.) and a dibromo-dihydro umbellulone C 10 H 14 OBr 2 

 (melting point 119 to 119,5°). The former can be reduced with zinc 

 dust and acetic acid into the saturated ketone C 10 H 16 O (boiling point 

 2 14° to 2 1 7 ). But when dibromo-dihydro umbellulone is treated 

 in this manner, only one bromine atom is eliminated, with formation 

 of bromo-dihydro umbellulone (melting point 58° to 59°). This, 

 however, can be further reduced with sodium in alcoholic solution to 

 tetrahydro umbellulol (boiling point 207° to 208° at 760 mm.; 

 d 15 o 0,9071; [aJpj — 6,6°). Both dibromo-dihydro umbellulone and 

 bromo-dihydro umbellulone behave as saturated compounds. 



On oxidation with cold 3 per cent, potassium permanganate solution, 

 umbellone readily passes over into a lactone C 9 H 12 2 of the boiling 

 point 2 1 7 to 221 . Tetrahydro umbellulol is a colourless liquid 

 possessing a camphor- and borneol-like odour. 



Waterfennel Oil. During the examination of an oil of water- 

 fennel freed from phellandrene, we observed that the oil imparted 

 a deep red colour to fuchsin sulphurous acid. When shaken with 

 sodium bisulphite solution a crystalline bisulphite double-compound soon 

 separated off from which, after washing with alcohol and ether, an 

 aldehyde was liberated by means of soda. In order to remove all 

 impurities not reacting with sodium bisulphite, the same purification- 

 process was repeated, and the aldehyde then distilled, first with water- 

 vapour and subsequently in vacuo. Apart from the first runnings 

 which contained only a few drops, it had the constant boiling point 89° 

 (5 mm. pressure) and the following properties : d 15 o 0,9445 ; «d — 36° 30'; 

 n D 1,4911. Its odour reminds strongly of cuminic aldehyde. On closer 

 examination the aldehyde was found to be an isomeride of citral 

 C 10 H 16 O, to which we would give the name "phellandral". In 

 order to identify it, we have first of all produced some derivatives 

 and analysed these, and subsequently made some oxidation tests so 

 as to obtain an insight into its constitution. 



The semicarbazone was produced in the usual manner in acetic 

 solution. It crystallises from alcohol (in which it is rather difficult 

 to dissolve), in the form of small crystals of the melting point 202° 

 to 204°. 



