Straightforward synthesis of (1S)-10-dimethylaminomethylcamphor: an enantiospecific model procedure to C10C-substituted camphor-derived chiral sources

Enantiopure 3,3-dimethyl-2-methylenenorbornan-1-ol, readily obtained from commercially available camphor, is able to react with Eschenmoserʹs salt under very soft reaction conditions. This reaction constitutes the first example in which a non-mesomerically activated olefin easily adds the Eschenmoserʹs salt. The addition takes place regiospecifically and it is followed by an enantiospecific Wagner–Meerwein rearrangement of the norbornane skeleton to afford enantiopure 10-dimethylaminomethylcamphor, an interesting chiral δ-amino ketone, with excellent yield. The obtained amino ketone is a key intermediate to new valuable C10C-substituted camphor-derived chiral sources.