The structure of zizanoic acid, a novel sesquiterpene in vetiver oil

✍ Scribed by Fusao Kido; Hisashi Uda; Akira Yoshikoshi

• Publisher: Elsevier Science
• Year: 1967
• Tongue: French
• Weight: 307 KB
• Volume: 8
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)90865-7

✦ Synopsis

Isolation of acidic constituents from the essential oil of vetiver (Vetiveria zizanoides Stapf) has been reported by several investigators. 2-4) We have also isolated a sesquiterpene carboxylic acid from the essential oil of the vetiver cultivated in Japan. We propose the name zizanoic acid for this carboxylic acid5) and wish to report evidence for its proposed structure I.

The acidic portion was extracted from the essential oil with aqueous alkali and purified, after conversion into methyl ester with diazomethane, by fractional distillation and chromatography on silica gel. Pure zizanoic acid, 6, Cl5H2202, was obtained, after alkaline hydrolysis of the methyl ester, in approximately 0.4s yield from the essential oil and showed the following properties: 3 :8,9 7) 2600, 1700 (-COOH), 1640, 892 (>C=CH2) cm-'; g cc'4 1.05, 1.08 (s., 3H, each), 2.62 (q., 1H; >CK-COOH), 4.53, 4.70 (t., lH, each; ;C=CHa), 11.08 (s., 1H; -COOH); cyclohexylamine salt, m.p. 146' The methyl ester (II), C1eHe40e, b.p.