Absolute configuration of carbon 2 in the chromene ring of gambogic acid

✍ Scribed by G. Cardillo; L. Merlini

• Publisher: Elsevier Science
• Year: 1967
• Tongue: French
• Weight: 117 KB
• Volume: 8
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)70340-6

✦ Synopsis

A few n-methyl-2(4'-methylpent-3 I-enyl)-ohromenes, gambogio acid (2--6), oannabichromene (7), and flemingins (8) have been recently found in Nature. Except for gambogio acid (S), they have only one asymmetric oenter, i.e. the carbon 2 of the chromene ring. We have now established the absolute configuration of this center in the most easily available of these chromenes, gsmbogio acid, by -0, oqdation of the corresponding chroman (10). Catalytic hydrogenation of gambouio acid (I) ([air---648O, UeOH, 0 -1.06