Zur Kenntnis der Triterpene. 193. Mitteilung. Synthese von (±)‐ trans ‐4,4,7,9‐Tetramethyl‐3β‐hydroxy‐decalon‐(8)

Racemic trans‐4,4,7,9‐tetramethyl‐3 β‐hydroxy‐decalone‐(8) (Xa) has been synthesized. The corresponding optically active levorotatory compound had been previously obtained by R. Rüegg, J. Dreiding, O. Jeger and L. Ruzicka, as a degradation product of α‐amyrin. The stereoisomer racemic cis‐4,4,7,9‐tetramethyl‐3 α‐hydroxy‐decalone‐(8) (XIVa) and the two hydroxyketones (±)‐trans‐4,4,7‐trimethyl‐3 β‐hydroxy‐decalone‐(8) (XIIIa) and (±)‐cis‐4,4,7‐trimethyl‐3 β‐hydroxy‐decalone‐(8) (IXa) have also been obtained as secondary products of the synthesis.