Evaluation of Several Routes to Advanced Pregabalin Intermediates: Synthesis and Enantioselective Enzymatic Reduction Using Ene-Reductases

This publication describes the evaluation of four synthetic routes to the advanced pregabalin (Lyrica) intermediate 7. Asymmetric reduction of (E)-7 with an ene-reductase (OPR1 from Lycopersicon esculentum) gave a saturated cyanoester intermediate 5 with the desired S stereocenter in >99% ee. OPR1 also catalyzed the reduction of (Z)-7 to (S)-5, but with lower conversion and selectivity.