14-Hydroxycaryophyllene 4,5-oxide — A new sesquiterpene fromBetula pubescens
A new sesquiterpene — 14-hydroxycaryophyllene 4,5-oxide — has been isolated from the unsaponifiable part of an ethereal extract of the leaves ofBetula pubescens, and its structure has been established on the basis of chemical and spectral characteristics.
Base-catalyzed intramolecular displacements on certain 1,2-epoxides
Intramolecular displacement by hydroxyl on the 1,2-epoxide group under basic or neutral conditions has been studied for seven of the stereoisomeric 1,2-diols derived by oxidation of the exocyclic double bond of 1. In six of the examples (the seventh is ambiguous) the single or largely predominant product is that one of the less strained cis-fused isomers which has the fewer unfavourable steric interactions leading to it, without regard to whether the displacement occurs at the secondary or tertiary epoxide carbon.
Goyazensolide, a schistosomicidal heliangolide from Eremanthus goyazensis
Abstract Isolation and structure determination of goyazensolide, a new heliangolide responsible for the schistosomicidal properties of Eremanthus goyazensis Sch.-Bip., is reported.