The 30,60-bis-tertbutyldimethylsilylether 8, obtained from morphine (1
), reacts with dichloromethylmethylether and titanium(IV)-chloride to
yield the l-formyl compound 9. The morphine-1-carbaldehyde (4a) is rec
eived by acidic hydrolyzation of 9. Reaction of 1 with methenamine in
trifluoroacetic acid affords a mixture of aldehydes 4a and 4b, from wh
ich the morphine-2-carbaldehyde (4b) can be isolated.