Ring-equilibration

The decalin (bicyclo[4.4.0]decane) ring system provides another important system for study of conformational effects in cyclohexane rings. Equilibration of the cis and trans isomers reveals that the trans isomer is favored by about 2.8 kcal/mol. Note that this represents a change in configuration, not conformation. The energy difference can be analyzed by noting that the cis isomer has three more gauche butane interactions that are... 

Primary alkylaminosilanes and -silazanes also have been reported to undergo a deamination (equation 4) and ring equilibration (equation 5) when heated with catalytic amounts of ammonium salts (20). 

Table 3. Ring-Ring Equilibration (t-BuSiMe) Isomers ...

The Li salt of the disubstituted four-membered ring equilibrates to the Li salt of the six-membered ring ... 

Allcock, H.R. Schmutz, J.L. Kosydar, K.M. A new route for poly(organophosphazene) S3mthesis. Polymerization, copolymerization, and ring-ring equilibration of trifluoroethoxy- and chloro-substituted cyclotriphosphazenes. Macromolecules 1978, 77(1), 179-186. 

Constrain the alkene in a ring Equilibration to the more stable isomer... 

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