836 X. THE VITAMIN K GROUP 



Q 



0-CCH, 

 H I =" - 



^\ /\ P 



CH, CH, CH, CH, HC' C '^CCHoCH 



t I I L I i| I 



CH-jCHCHjCHgCHgCH CHgCHjCHgCHCHjCHgCHgC— O ^jp u p pu 



M S I 



0-CCH, 



II 

 



IK 

 Oxidation Products of Dihydrovitiimin Ki 



(2) Constitution of Vitamin K-i 



Vitamin K2 has been shown^^ to have the empirical formula of C41H56O2. 

 On the basis of reactions similar to those employed for the establishment of 

 the formula for vitamin Ki, Binkley et al.^^ and Karrer and Epprecht^^ 

 have assigned formula (X) to vitamin Ko, which is 2-methyl-3-difarnesyl- 

 1 ,4-naphthoquinone . 



HC C C OH, pii /^ii 



I II II I ^ I ^ 



HC, C, CCH,CH=(CCH,CH,CH=).CCH. 



V V 



H II 







X 



The nature of the cyclic portion of the molecule has been established by 

 methods similar to those employed in the case of vitamin Ki. Upon reduc- 

 tive acetylation, dihydrovitamin K2 diacetate (XI) is formed in a manner 

 analogous to that which occurs in the case of vitamin Ki. This indicates 

 the presence of the 2 oxygens in the quinoid structure. The absorption 

 spectrum, which is similar to that for vitamin Ki, also confirms the presence 

 of a quinone structure/^ 



^^9 9 t^i CH, CH, 



II I I 



HC. C .CCH,CH=(CCH-CH,CH=).CCH, 



VV 



H 1 



O-CCH, 

 II ' 

 



IE 

 53 p. Karrer and A. Epprecht, Helv. Chim. Acta, 23, 272-283 (1940) 



