578 VI. CAROTENOIDS AND RELATED COMPOUNDS 



metallic luster, which melt at 123-124°C. The diacetate is hypophasic. 

 It is quite soluble in ethanol, diethyl ether, benzene, and carbon disulfide, 

 less so in acetone, and it is practically insoluble in hexane. When concen- 

 trated hydrochloric acid is added to an ethereal solution, it assumes a deep 

 blue color. 



H3C CHj HjC CH, 



Q CH3 CH3 CH3 CH3 Q 



/ \//W W I HHH I HHHH I HHH I HH\/\ 



HzC C'C:C-C:C'C:C'C:C'C:C'C;C'C:C'C:C'C:C-C CHj 



H\l l/H 



C C=0 CH2 c 



"" C CHj H3C C 



H? Hz 



Capsaiithinone 



(e) Anhydrocapsanthinone, C40H66O4. Anhydrocapsanthinone can be 

 synthesized from capsanthinone diacetate by the removal of one molecule of 

 water, ^^^ using a reaction analogous to that employed for the preparation of 

 anhydro-/3-semicarotenone from semi-/3-carotenone.^^ It can be separated 

 from methanol in small red crystals which do not have a sharp melting 

 point. ^^ When partitioned between methanol and petroleum ether, the 

 pigment passes into the lower layer (methanol). 



Anhydrocapsanthinone 



(/) Capsanthylnl, C30H42O?,. This aldehyde originates when capsanthin 

 diacetate is oxidized with chromic acid, using an excess of the oxidizing 

 agent. ^■'^ Capsanthylal ciystallizes from 80% methanol in star-shaped 

 needles which melt at 127°C. It is quite soluble in benzene, ethanol, and 

 carbon disulfide, but poorl}'- so in petroleum ether. The aldehyde can be 

 identified by converting it to the monoxime, C30H43O3N, which melts at 

 184°C. 



H,C CHj 



CHj CH3 CH3 CH3 c 



0^ IhmhIhhhhIhhhIhh /\ 

 HC'C:C'C:C'C:c*C:C-C:C-C:C'C:C'C:C- C=0 CHz 



l/H 

 CHz C 



/ \ / \0H 

 H3C c 



Hi 



Capsanthylal 



