摘要 |
The invention relates to an optimized synthesis of pregabalin and additional 4-aminobutane acids using an improved method for producing conjugated nitroalkenes. This is achieved by a nitro-aldol reaction of an aliphatic aldehyde with a nitroalkane in the presence of a suitable diamine directly followed by an elimination of the conjugated nitroalkene by adding an acid, a subsequent catalyzed asymmetrical 1,4-Michael addition of a suitable nucleophile, and a subsequent retro-Claisen reaction or a hydrolosis and decarboxylation with a concluding reduction to 4-aminobutane acid. |