The Synthesis of the High-Potency Sweetener, NC-00637. Part 1:  The Synthesis of (<i>S</i>)-2-Methylhexanoic Acid

Abstract

The synthesis of the high potency sweetener candidate NC-00637 ( 1 ) required large quantities of ( S )-2-methylhexanoic acid ( 2 ). This acid was first prepared in small quantities by the use of chiral auxiliaries. For large quantities, resolution by classical means and an enzymatic method were investigated. Asymmetric hydrogenation provided a workable solution.