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Unformatted text preview: hexane rings that are joined together into a steroid skeleton. Parts ( a ) through ( e ) are concerned with positions 1, 4, 7, 11, and 12 in that order. The following diagram shows the orientation of axial and equatorial bonds at each of those positions. ( a ) At C-1 the bond that is cis to the methyl groups is equatorial (up). ( b ) At C-4 the bond that is cis to the methyl groups is axial (up). Both methyl groups are up. CH 3 CH 3 e c a b d 4 1 11 12 7 O HOCH 2 OH HO OH HO One axial OH substituent written in its most stable conformation as O HOCH 2 OH HO HO OH written in its most stable conformation as All substituents equatorial O CH 2 OH OH HO HO HO OH OH O CH 2 OH HO HO A: More stable stereoisomer Van der Waals strain destabilizes B H H H H CONFORMATIONS OF ALKANES AND CYCLOALKANES 61...
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- Spring '01
- Organic chemistry