𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Säurekatalysierte Umlagerung von 7-Hydroxy-royleanon in ein 20(10→9) abeo-Abietan-Derivat und zwei Phenalenone

✍ Scribed by Marcel Hensch; Conrad Hans Eugster; Hans-Peter Weber


Publisher
John Wiley and Sons
Year
1975
Tongue
German
Weight
717 KB
Volume
58
Category
Article
ISSN
0018-019X

No coin nor oath required. For personal study only.

✦ Synopsis


Acid‐catalyzed rearrangement of 7‐hydroxyroyleanone into a 20(10→9) abeo‐abietane derivative and two phenalenones

Short treatment of either horminone (1b), taxoquinone (1a), 6,7‐dehydroroyleanone (3) or 6β‐hydroxyroyleanone (1c) with 80% H~2~SO~4~ at 0° leads to a mixture of rearranged products. Two of the structures, determined by X‐ray‐cristallography, were found to be (9__R__, 10__R__)‐20(10→9)‐abeo‐12‐hydroxy‐5,7, 12‐abietatriene‐11,14‐dione (4) and 9‐isopropyl‐2,2,5‐trimethyl‐8__H__‐phenaleno[1,9‐bc]furan‐8‐one (5), and the third compound, isolated in very small amounts, has been provisionally identified as 3‐hydroxy‐9‐isopropyl‐2,2,5‐trimethyl‐8__H__‐phenaleno[1,9‐bc]furan‐8‐one (6) from the spectroscopic data.