802. Modified steroid hormones. Part XXIII. Some pentacyclic types

Cooley, G.; Ducker, J.W.; Ellis, B.; Petrow, V.; Scott, W. P.

doi:10.1039/jr9610004108

Cited by 7 publications

(1 citation statement)

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“…However, the construction of the precursor 8 with some confidence in the regio- and stereochemistry of the additional ring was a more challenging task. Pentacyclic steroid homologues with trans A/B ring fusions have been known for almost 50 years, − but we know of no comparable A/B-cis-fused pentacycles such as 8 . (In this paper, the four original steroid rings are designated A−D, as is conventional; the extra ring of the pentacycle that is fused to ring A is designated E.)…”

Section: Resultsmentioning

confidence: 99%

The Supertristeroids: Large, Chiral, Molecular Bowls Prepared by Trimerization of Pentacyclic Steroidal Ketones

Song

Pascal

2007

J. Org. Chem.

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Robinson annulation of coprostanone (1) at the 2,3- and 3,4-positions gave two pentacyclic enones (7 and 10) that contain A/B-cis-fused ring junctions. Reduction of these enones gave the pentacyclic steroidal ketones 2 alpha,3beta- (8) and 2 alpha,3 alpha-(3'-oxocyclohexano)-5 beta-cholestane (9) and 4 alpha,3beta- (11) and 4 alpha,3 alpha-(3'-oxocyclohexano)-5 beta-cholestane (12). The structures of compounds 8, 9, and 11 were unambiguously established by X-ray analysis. TiCl4-promoted trimerization of compounds 8 and 11 gave the "supertristeroids" 4 and 5, respectively: large (C93) chiral, hydrocarbon clefts with C3-symmetric pockets approximately 12 A in diameter.

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Section: Resultsmentioning

confidence: 99%