Hopane rearrangement

Moldowan JM, Fago FJ, Carlson RMK, Young DC, van Duyne G, Clardy J, Schoell M, PtUinger CT, Watt DS, Rearranged hopanes in sediments and petroleum, Geochim Cosmochim Acta 55 3333-3353, 1991. 

Confirmation of the C-2ipH configuration in the hopane series has resulted from the X-ray analyses of adiantol (133) and zeorin (134).This has led to a reinterpretation of a previously reported correlation of zeorin and leucotylin (135). Full papers on the rearrangement of some tetrasubstituted epoxides in this series have appeared. 

Berti et al. found that the tetrasubstituted epoxide derivative (110 equation 44) of the triterpene hopane gave an efficient rearrangement to the ketone (111). 

Two new rearranged hopanes, alangidiol (178) and isoalangidiol (179), with a d-e cis fusion have been reported from the leaves of Alangium lamarckii. New fernene derivatives which have appeared this year include fern-9(l l)-en-6a-ol (180) and fern-9(ll)-en-20j8-ol (181) from the rhizomes of Polypodium juglandifolium and hortensol (182) from the leaves of Evodia hortensis The structure of (182) was confirmed by A"-ray analysis. 

MoldowanJ.M., Fago EJ., Carlson R.M.K., Young D.C., Van Duyne G., ClardyJ., Schoell M., Pillinger C.T., Watt D.S. (1991) Rearranged hopanes in sediments and petroleum. Geochim. Cosmochim.Acta 55, 3333—53. 

Although some 50 compounds with hopane skeleton (556) have been obtained so far from nature, their occurrence in woody tissues is quite rare. Hydrox-yhopanone (561) is a component of dammar from Hopea micrantha (229). Moretenol (562), from bark of Sapium sebiferum, is an example of a C-21aH hopane apparently this compound results from C-C-C-C-B folding of squalene. To date, none of the rearranged hopane types depicted in Fig. 8.1.33 has been reported to occur in woody parts of plants. 

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