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7-Acetoxy-cochinchinone I.

ABSTRACT: The title compound {systematic name: 12-[(2E)-3,7-dimethyl-2,6-octa-dien-yl]-5,8-dihydr-oxy-2,2-dimethyl-2H,6H-pyrano[3,2-b]xanthen-6-one}, C(30)H(32)O(6), has four fused rings (A/B/C/D) and the xanthone ring system (A/B/C) is essentially planar, with dihedral angles of 1.85?(13) and 2.47?(13)°, respectively, between rings A and B, and between rings B and C. The chromene ring D is in a sofa form. The geranyl side chain is axially attached to ring C with an (-)-synclinal conformation. The 3-methyl-2-butenyl terminal of the geranyl side chain is disordered with the site-occupancy ratio of 0.513?(5):0.487?(5). The acet-oxy group is attached axially to ring A with an (+)-synclinal conformation. An intra-molecular O-H?O hydrogen bond involving the carbonyl and hydroxyl groups generates an S(6) ring motif. In the crystal, weak C-H?O and C-H?? inter-actions, and ?-? inter-actions with centroid-centroid distances of 3.6562?(16) and 3.6565?(16)?Å are observed.

SUBMITTER: Chantrapromma S

PROVIDER: S-EPMC2970046 | biostudies-literature | 2009 Aug

REPOSITORIES: biostudies-literature

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7-Acetoxy-cochinchinone I.

Chantrapromma Suchada S Boonnak Nawong N Fun Hoong-Kun HK

Acta crystallographica. Section E, Structure reports online 20090822 Pt 9

The title compound {systematic name: 12-[(2E)-3,7-dimethyl-2,6-octa-dien-yl]-5,8-dihydr-oxy-2,2-dimethyl-2H,6H-pyrano[3,2-b]xanthen-6-one}, C(30)H(32)O(6), has four fused rings (A/B/C/D) and the xanthone ring system (A/B/C) is essentially planar, with dihedral angles of 1.85 (13) and 2.47 (13)°, respectively, between rings A and B, and between rings B and C. The chromene ring D is in a sofa form. The geranyl side chain is axially attached to ring C with an (-)-synclinal conformation. The 3-methy ...[more]

PMID: 21577623

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