Proof of the Absolute Configuration of (−)-(S)-2-Hydroxy-β-ionone by correlation with ursolic acid and with (−)-trans-verbenol

✍ Scribed by Sina Escher; Wolfgang Giersch; Günther Ohloff

• Publisher: John Wiley and Sons
• Year: 1981
• Tongue: German
• Weight: 970 KB
• Volume: 64
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19810640402

✦ Synopsis

Abstract

(−)‐(S)‐2‐Hydroxy‐β‐ionone (33), (+)‐(2 S, 6 S)‐2‐hydroxy‐α‐ionone (34), and their acetates 35 and 36 have been synthesized from (+)‐(S)‐6‐methylbicyclo [4.3.0]‐non‐1‐ene‐3, 7‐dione (3). The key intermediate (+)‐(1 R, 3 S, 6 S)‐2, 2, 6‐trimethyl‐7‐oxobicyclo [4.3.0]non‐3‐yl acetate (7) was correlated with a degradation product of the pentacyclic triterpene ursolic acid (16). Compound 33 was also synthesized by an alternative route starting from (−)‐trans‐verbenol (42).