R. Haag et al., HIGHLY EXO-SELECTIVE EPOXIDATION AND HYDROXYLATION OF TRIQUINACENE AND ITS DERIVATIVES - ALL-EXO-HEXAHYDROXYTRIQUINANE, Journal of organic chemistry, 63(8), 1998, pp. 2544-2547
Epoxidation of triquinacene 3 with dimethyldioxirane proceeded with a
high degree of exo-face selectivity to give a quantitative yield of a
1:1.5 mixture of all-exo-4a and endo, exo, exo-triepoxytriquinane 4b.
Subsequent lithium aluminum hydride reduction of the all-exo-triepoxid
e 4a gave all-exo-2,5,8-5a and all-exo-2,5,9-trihydroxytriquinane 5b,
respectively. The straightforward S-fold dihydroxylation of triquinace
ne 3 led exclusively to the all-exo-hexahydroxytriquinane 8 in one ste
p. X-ray crystal structure analyses confirmed the configuration of the
triepoxide 4b and the hexaacetate 9 of the hexol 8.