Infrared Spectra of Santonin Isomers¹

Isolation and Structural Elucidation of Four Sesquiterpenes fromChloranthus japonicus(Chloranthaceae)

“…The geometry of the two double bonds and the absolute configuration of the asymmetric center at C-8 were not mentioned in the literatureP) Diisobutylaluminum hydride reduction l l ) of 3 yielded a furano-derivative (4), which was identical with isofuranodiene (E,E-isomer, see below) in the physicochemical properties. Thionyl chloride treatment 1 5) of 3 gave a trans annular ring closure product (10). This eudesmanolide has been previously known as the autooxidation product of atractylon l6 ) and recently isolated from natural source and named atractylenolide II by Endo etal.…”

“…The residue was chromatographed over 20% AgN03-Si02 and eluted with a hexane--ether gradient. Ether-hexane (1: 4 and I: I) eluates were evaporated and cooled to yield a eudesmanolide (10) Table II were used for the antifungal test. The inhibitory activity was determined by the paper disc method; paper disc: Toyo paper disc (thick) 8 mm in diameter; culture medium: glucose (3 %), peptone (I %), yeast extract (0.1 %) and agar (0.8%).…”

Essential Oils and Related Products

“…Kataoka (86), by means of Raman spectra, detected a-pinene, (3-pinene, and dipentene in essential oils. Kanzawa et al (83) examined the infrared absorption spectra of santonin and its isomers. By observing the position and intensity of two characteristic bands in the 1300 to 1900 cm.-1 range, the stereochemical configuration of the lactone ring can be determined.…”