Fenchones, Wagner-Meerwein rearrangement

The ring strain at this point in the biosynthesis can also be relieved by means of a Wagner-Meerwein rearrangement (see Chapter 5 for details of this reaction) to produce the much less strained fenchane system. Addition of water, followed by oxidation, gives the ketone, fenchone. 

The Martinez group has demonstrated the versatility of the Wagner-Meerwein rearrangement in the enantiospecific synthesis of C(10)-substituted camphors and fenchones from readily available (-i-)-camphor (103) and (-)-fenchone (104). These derivatives represent a multitude of substitution tjmes, including C(10)-O-, C(10)-Br-, C(10)-S-, C(10)-Se-C(10)-N-, C(10)-C-N-, and C(9,10)-dihalocamphors. They are of... 

---