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Die Ableitung der Stereochemie von 1‐Isopropyl‐4‐methyl‐bicyclo[3.1.0]hexan ( cis ‐und trans ‐Thujan) durch Protonenresonanz‐Spektroskopie
Author(s) -
Dieffenbacher A.,
von Philipsborn W.
Publication year - 1966
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19660490212
Subject(s) - chemistry , cyclopentane , ring (chemistry) , stereochemistry , isopropyl , absolute configuration , bicyclic molecule , medicinal chemistry , organic chemistry
100 Mc/s proton NMR. spectra of the two diastereoisomeric thujanes obtained by reduction natural thujone have been measured and are given a detailed analysis. The relative configurations of the two hydrocarbons are deduced. Together with the known R ‐configuration at C(1) the absolute configurations can be derived, (−)‐ cis ‐thujane having the (1 R :4 S :5 R )‐ and (+)‐ trans ‐thujane the (1 R :4 R :5 R )‐configuration. It can be shown that the trans ‐isomer adopts a boat‐like conformation of the bicyclohexane ring system whereas cis ‐thujane prefers a half‐chair conformation with a flattened cyclopentane ring.