(-)-α-Santonin has been correlated stereochemically with (+)-11-carboxy-3-oxoeusanton-4-enic acid (X) and by the investigation of molecular rotation of the latter the absolute configuration of the former has been deduced. It has been shown that(-)-α-santonin belongs to the same stereochemical type as steroids.(-)-β-Santonin proved to be the C11-epimer of (-)-α-santonin.
