Stabilities for the eight isomeric forms of the steroid skeleton (perhydrocyclopentanophenanthrene)

Authors
Tantuco, K Deretey, E Csizmadia, IG
Citation
K. Tantuco et al., Stabilities for the eight isomeric forms of the steroid skeleton (perhydrocyclopentanophenanthrene), J MOL ST-TH, 503(1-2), 2000, pp. 97-111
Citations number
11
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM
ISSN journal
01661280 → ACNP
Volume
503
Issue
1-2
Year of publication
2000
Pages
97 - 111
Database
ISI
SICI code
0166-1280(20000509)503:1-2<97:SFTEIF>2.0.ZU;2-L
Abstract
The relative stabilities for the eight isomers of the steroid skeleton resu lting from three ring fusions (A/B, B/C, CID) were determined using molecul ar mechanics (MM+), semi-empirical (AMI and PM3), and ab initio HF/3-21G mo lecular orbital calculations. Five of the isomers studied, (trans, trans, t rans), (cis, trans, trans), (trans, trans, cis), (trans, cis, trans), and ( cis, trans, cis) occur naturally. The calculated relative energies for the three methods gave conflicting results. The ab initio order of stability wa s the following: (trans, trans, trans) > (trans, trans, cis) > (trans, cis, trans) > (cis, trans, trans) > (trans, cis, cis)>(cis, trans, cis)> (cis, cis, trans)> (cis, cis, cis). (C) 2000 Elsevier Science B.V. All rights res erved.