10 Variotinの立体配位

概要

論文の詳細を見る
Variotin, an antifungal antibiotic produced by Paecilomyces varioti Bainier var. antibioticus, has the molecular formula of C_<17>H_<25>O_3N. The chemical structure of variotin(I) has been previously reported by the authors. Ozonolysis of acetylvariotin in chloroform followed by oxidative degradation with silver oxide in basic solution gave D(-)-α-hydroxycaproic acid, therefore the configuration at the 8' position is R. Information cocerning the configuration of the 2' and 4' double bonds was obtained from the n.m.r. spectrum. The coupling constants revealed a trans-trans configuration for 2' and 4' double bonds. Relatively ready formation of the adduct by Diels-Alder reaction reconfirmed the presence of trans-trans configuration in the conjugated system. The adduct is white needle crystal; C_<21>H_<27>O_6N, m.p. 137-137.5°. From the physicochemical evidences, the seven membered lactone formation between the 8' hydroxy and a carboxyl of the adduct was confirmed. This fact indicated that the 6' double bond must adapt a cis configuration. In conclusion, the stereochemical structure for variotin is N-(8'-R-hydroxy-6'-methyl-trans-trans-cis-dodeca-2',4',6'-trienoyl)-2-pyrrolidone.
天然有機化合物討論会の論文
1966-09-15