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Neue spiro ‐Cyclopropyl‐cyclohexendion‐Diterpene: Coleone M, N, P, Q, R sowie Barbatusin aus Plectranthus caninus R OTH und Coleon O aus Coleus somaliensis S. M OORE
Author(s) -
Arihara Shigenobu,
Räedi Peter,
Eugster Conrad Hans
Publication year - 1975
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19750580203
Subject(s) - coleus , chemistry , plectranthus , stereochemistry , diterpene , raceme , cyclopropane , chirality (physics) , botany , lamiaceae , physics , biology , organic chemistry , ring (chemistry) , nambu–jona lasinio model , chiral symmetry breaking , inflorescence , quantum mechanics , quark
The yellow glands on the leaves and racemes of Plectranthus caninus R OTH ( Labiatae ) are a rich source of spiro ‐abietanes. Five new coleons have now been isolated, together with barbatusin, and their structures have been determined. Coleon O occurs in similar glands of Coleus somaliensis S. M OORE . From the biogenetic point of view the simultaneous occurrence of both structures with normal gem. C(4)‐dimethyl group, and rearranged δ 3,4 ‐19 (or 18) (4 → 3) abeo ‐abietan‐structures appears most remarkable. We discuss the origin of the unusual spiro ‐cyclopropane structure with respect to the various oxygen functions present in these molecules. The application of the excitonchirality rule of Nakanishi et al. allows the determination of the chirality at C(7).