RECENT WORK ON THE MORPHINE GROUP 295 



"bridge" carbon atoms of the phenanthrene complex, and 

 corresponds to a hydroxyl group, which in both hydroxy- 

 codeine and hydroxymethylmorphimethine possesses alcoholic 

 properties. Hence the " bridge " nucleus must be reduced — an 

 inference which is supported by the fact that hydroxycodeine 

 is formed from codeine by oxidation with chromic acid 

 (see p. 300). The way in which the hydrogen atoms are 

 distributed between the two reduced nuclei and the position 

 of the double bond depend upon the points of attachment 

 of the nitrogen complex, regarding which there is some 

 difference of opinion. Thus Pschorr suggests that it is joined 

 to positions 8 and 9 ; Knorr to positions 5 and 9 ; while 

 Freund considers that it forms a bridge between positions 5 

 and 8. These views have found expression in the following 

 formulae : 



H H H 



N.CH :i 



HOH 



H„ 



Morphine (Pschorr) 



H 2 



Morphine (Freund) 



H, 



Morphine (Knorr) 



Pschorr's formula necessitates the following expression for 



methylmorphimethine : 



H 

 CH,0 



N . (CH 3 ) 2 



HOH 



