Guaiane, Pseudoguaiane

Taylor, A. Suzuki, and S. Tamura, Tetrahedron Letters, 1977, 1169. 

3-epoxyambrosin (448) from the aerial parts of Ambrosia cumanensis and isoguaiene (449) and 11-hydroxyisoguaiene (450) from the roots of Parthenium hysterophorus. 

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New additions to the guaiane family include sclerosporin (609), sclerosporal (610), sclerosporene (611), the guaienes (612) and (613) [which co-occurs with precatabrone (614)], and the guaioxide (615). The unusual pseudoguaiane caespitenone (616) has been isolated from the liverwort Porella caespitans This compound co-occurs with (-i-)-aristolone (617) and (-)-a-eudesmol (618), which are enantiomeric to those found in higher plants. 

The same kind of rearrangement has been utilized in an intramolecular sense to transform the much more readily available decalin system into the bicyclo[5.3.0]decanes of the guaiane and pseudoguaiane sesquiterpenes. Thus, the Heathcock group synthesized confertin, as shown in Scheme 46 [82]. 

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