Cryptocarya latifolia

The presence of acetate substituents on the side chain at C-6 is very common. Compounds (40) and (41) were isolated by Drewes et al from the bark of Cryptocarya latifolia trees in their investigations of the chemistry of plants used for magical and medicinal purposes by the Zulu people (55). The CD spectra of these two compounds show a positive Cotton effect and hence they possess the (67 )-configuration. Saponification followed by acetonide formation of (40) afforded two acetonides (42) and (43) (50). A (2 7 ,6 5)-stereochemistry followed from application of the MTPA determination rule (24) to the (/ )- and (5)-MTPA esters of these acetonides. A (4 5)-stereochemistry was assigned from the syn-diol relationship of the two acetal oxygen atoms in (42) and (43) as determined from their C NMR spectra (57). Thus the acetonide rings in both compounds possessed chair conformations with the alkyl... 

Compound (80), a structural isomer of umuravarumbolide (55), is a minor constituent of Cryptocarya latifolia 89). The immunosuppressive agent, (—)-PA-48153 (81), has been isolated from Streptomyces prunicolor sp. PA 48153 (90). The same compound, obtained from Streptomyces sp. NK10958 and shown to be a plant growth regulator, has been named pironetin, and the structure based on spectral data, confirmed by X-ray analysis 91, 92) and synthesis 93). 

Collett, L.A., M.T. Davies-Coleman, D.E.A. Rivett, S.E. Drewes, and M.M. Horn Absolute Configuration of a-Pyrones from Cryptocarya latifolia and Syncolostemon densiflorus. Phytochem., 4, 935 (1997). 

Drewes, S.E., M.M. Horn, and C.S. Wijewardene a-Pyrone from Cryptocarya latifolia - A Structural Isomer of Umuravumbolide. Phytochem., 41, 333 (1996). 

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