Acifran

Acifran is a niacin receptor agonist.

It is synthesized from acetophenone and the anion of 1-methyl-2,6-dithiolane (2) (prepared using BuLi). The latter is a reversed polarity version of acetaldehyde (Umpolung) whose condensation with 1 produces tertiary alcohol 3 by carbonyl addition. Acid-catalyzed dithiolane exchange with pyruvate leads to α-hydroxyketone 4. This last undergoes base-catalyzed oxylation on the methyl ketone moiety and cyclodehydration and ester hydrolysis to produce acifran 5.