The First Synthesis of (4S,5R,6R)‐5,6‐Dihydroxy‐4‐(prop‐1‐en‐2‐yl)cyclohex‐1‐ene‐1‐carboxylic Acid

A putative acid metabolite of a novel highly effective antiparkinsonian agent, (4S,5R,6R)-5,6-dihydroxy-4-(prop-1-en-2-yl)cyclohex-1-ene-1-carboxylic acid (5), was synthesized for the first time. Several synthetic approaches based on different transformations of O-bearing monoterpenoids of the pinane and p-menthane series were developed and tested in the course of the study. Acid 5 was synthesized starting from a commercially available monoterpenoid, (−)-verbenone, in a total yield of 4.4% over eight steps.