3 AZAFRIN 283 



CHo CH^ 



\V 



C CH3 CH3 CH3 



/\ I I I 



CH2 CO- CH=CH- C=CHCH=CH- C=CHCH=CHCH=C- CH=CH- COOH 



CHis CO-CHa 



\ / Azafrinone 



CH2 



On ozonisation azafrin yields a : a-dimethylglutaric acid and geronic acid. 

 Chromic acid oxidation shows the presence of four side-chain methyl groups, 

 the position of which follows from the nature of the three products obtained 

 on thermal decomposition, namely w-xylene, toluene and w-toluic acid^^'. 

 CHo CHo 



\/ 



C OH CH3 CH3 CH3 



CH, C- CH=CH- C=CHCH=CH- C=CHCH=CHCH=C- CH=CH- COOH 



The formula of azafrin was further confirmed by Kuhn and Brockmann 

 by the conversion of azafrin into anhydroazafrinone amide which has also been 

 obtained from /3-carotene (cf. p. 134), thus proving the relation between the two 

 pigments^^". Chromic oxidation of azafrin yields azafrinone, which is converted 

 via the acid chloride into azafrinone amide : 



CHq OHq 



\V 



C CH-i CHo CHo 



y\ 1 1 1 



CHa CO- CH=CH- C=CHCH=CH- C=CHCH=CHCH=C- CH=CH- CONHj 



CH-j C0-CH3 



\ / Azafrinone amide 



CH2 



By the action of potassium hydroxide, azafrinone amide is converted into 

 anhydroazafrinone amide. 



CHo CHo * 



\/ 



/\ r I I 



CHj C- CH=CH- C=CHCH=CH- C=CHCH=CHCH=C- CH=CH- CONH,, 



CHj — C- CO- CHj Anhydroazafrinone amide 



References p. 2go-2g4. 



