Synthese von Naturstoffen mit Alkyl-methoxy-1,4-benzochinon-Struktur

✍ Scribed by Pfeifer, Jochen ;Gerlach, Hans

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 839 KB
• Volume: 1995
• Category: Article
• ISSN: 0947-3440
• DOI: 10.1002/jlac.199519950118

✦ Synopsis

Synthesis of Natural Compounds with Alkyl-methoxy-1 ,g-benzoquinone Structure

The 1,4-benzoquinones 1-7 occurring in various plants and having interesting biological properties have been synthesized from the tetrahydropyranyl ethers l ? and 21. Reaction with n-butyllithium gave selectively the ortho-lithiated compounds. These could be alkylated with the haloalkenes 13-16 and haloalkanes to give the substituted phenols 18-20 and 22-25 in high yield after methanolysis. Alkylations of the methoxyisopropylether 8 of 10-undecyn-1-01 with bromobutane and bromohexane gave 9 and 10. These alky-nols could be selectively hydrogenated with Lindlar-Palladium catalyst to give the (Z)-alkenols 11 and 12 which could be converted into the bromoalkenes 13, 14 and the iodoalkenes 15, 16. Oxidation of the phenols 18-20 and 22-25 with molecular oxygen in the presence of salcomine as catalyst produced the substituted lr4-benzoquinones 1-3 and 26-29 in high yield. Selective hydrolysis with perchloric acid converted 26-29 into the natural products 4-?. 7 R = [CH,],,Me lrisoquin (Iris missouriensis)

der fur die Synthese der Verbindungen 1-3 und die der hydroxysubstituierten Vertreter 4-7 gleichermal3en gut ge-