Synthesis of (2R,6R,10R)- and (2S,6R,10R)-Pristanic Acid Diastereomers

In this study, the synthesis of (2S,6R,10R) and (2R,6R,10R) diastereomers of pristanic acid is described. The key step in this synthesis is the dehomologation of (3RS,7R,11R)-dihydrophytol to one-carbon shorter (2RS,6R,10R)-pristanic acid using o-iodoxybenzoic acid. The diastereomeric mixture of pristanic acid is easily separated by silica gel column chromatography after conversion to the corresponding amides, which can be converted back to (2R,6R,10R)- and (2S,6R,10R)-pristanic acids in good yields.