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Redetermination and absolute configuration of (+)-7-epiclusianone.

ABSTRACT: The absolute configuration of 3-benzoyl-4-hy-droxy-6,6-dimethyl-1,5,7-tris-(3-methyl-but-2-en-yl)bicyclo-[3.3.1]non-3-ene-2,9-dione, C(33)H(42)O(4), isolated from Hypericum hypericoides, has been determined. The previous study [Xiao et al. (2007 ?). J. Nat. Prod.70, 1779-1782] gave only the established relative configuration. The three stereogenic centers are now established as 1R, 5R and 7S on the basis of the refinement of the Flack absolute structure parameter against Cu K? data and correspond to a specific rotation of [?](D) (20) = +66°. The enol-hy-droxy group forms an intra-molecular O-H?O hydrogen bond to close an S(6) ring.

SUBMITTER: Christian OE

PROVIDER: S-EPMC3515307 | biostudies-literature | 2012 Nov

REPOSITORIES: biostudies-literature

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Redetermination and absolute configuration of (+)-7-epiclusianone.

Christian Omar E OE Fronczek Frank R FR Ky Khoa K Pradhan Shreedu S Manandhar Anjela A Richmond Cecilia C

Acta crystallographica. Section E, Structure reports online 20121027 Pt 11

The absolute configuration of 3-benzoyl-4-hy-droxy-6,6-dimethyl-1,5,7-tris-(3-methyl-but-2-en-yl)bicyclo-[3.3.1]non-3-ene-2,9-dione, C(33)H(42)O(4), isolated from Hypericum hypericoides, has been determined. The previous study [Xiao et al. (2007 ▶). J. Nat. Prod.70, 1779-1782] gave only the established relative configuration. The three stereogenic centers are now established as 1R, 5R and 7S on the basis of the refinement of the Flack absolute structure parameter against Cu Kα data and correspon ...[more]

PMID: 23284527

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