The present invention is directed to a practical process for the
preparation of an enamide (II) by palladium catalyzed coupling of a
primary amide (IV) with a compound of structural formula (III), as shown
below: As well as to crystalline forms of a compound produced by this
process, in particular, an anhydrous crystal form, Form B, and
crystalline solvates falling into three patterns, Type 1, Type 2, and
Type 3, and crystalline intermediate compounds produced in the process.
Still further, the present invention relates to the stereoselective
reduction of the tetrasubstituted enamide (II) to the corresponding amide
(I).