In-out isomerism
In-Out isomerism , partly as out-in-isomerism called, a is stereochemical term , the position of the bridgehead protons at large, bicyclic ring compounds described in relation to the ring system. The term was introduced in 1968 by HE Simmons and CH Park. In the event that a nitrogen atom forms the bridgehead in large, bicyclic compounds, the in-out isomerism also describes the position of the lone pairs of electrons .
If the ring size of bicycles is large enough , with pure carbon rings from about eight members, with nitrogen-containing rings from about seven members, the bridgehead protons of a CH group or the lone pair of electrons of a nitrogen atom can be inside or outside the ring system. This results in in-in isomers, in-out isomers and out-out isomers. Since the isomers are formed by rotating around a single bond, they are atropisomers .
literature
- Roger W. Alder, Stephen P. East: In / Out Isomerism. In: Chemical Reviews . 96, 1996, pp. 2097-2112, doi : 10.1021 / cr940246k .
Individual evidence
- ^ HE Simmons, CH Park: Macrobicyclic amines. I. Out-in isomerism of 1, (k + 2) -diazabicyclo [klm] alkanes. In: Journal of the American Chemical Society . 90, 1968, pp. 2428-2429, doi : 10.1021 / ja01011a045 .
- ^ CH Park, HE Simmons: Bicyclo [8.8.8] hexacosane. Out, in isomerism. In: Journal of the American Chemical Society. 94, 1972, pp. 7184-7186, doi : 10.1021 / ja00775a071 .
- ↑ Wolfgang Bähr, Hans Theobald: Organic stereochemistry. Springer Verlag, 1973, ISBN 3-540-06339-0 , pp. 47-48.