Abstract
Pathways of the acid catalyzed multiple step isomerization (adamantane rearrangement) of tricycloundecanes are reviewed. 1. Introduction. Characteristics of adamantane rearrangements. 2. Rearrangement pathways of tricycloundecanes. 2.1 cis-exo- and -endo-Tetramethylenenorbornane (exo-7 and endo-7). (1) Structure determination of the intermediates. (2) Rearrangement of cis-endo tetramethylenenorbornane (endo-7) and that of the exoisomer (exo-7) in the presence of 1-methyl- adamantane. (3) Timeconversion studies. (4) Rearrangement pathways. 2.2 cis-2, 3-Trimethylenebicyclo [2.2.2] octane (20). (1) Structure determination of the intermediates. (2) Rearrangement pathways. 2.3 cis-endo-6, 7-Trimethylenebicyclo [3.2.1] octane (endo-14). 2.4 Enhancement of the rearrangement rate for endo vs. isomers in cis-2, 3-tetramethylenenorbornanes (7) and cis-6, 7-trimethylenebicyclo [3.2.1] octanes (14). 3. Rearrangement pathweys of tricycloundecanols and tricycloundecenes. 3.1 Hydride transfer reduction-rearrangement of cis-exo-5, 6-trimethylene-2-norbornyl carbinol (30), cis-exo-6, 7-trimethylenebicyclo [3.2.1] octan-2- and -endo-3-ol (31 and 32), and cis-endo-5, 6-trimethylenebicyclo [2. 2.2] octan-exo- and -endo-2-ol (33x and 33n). (1) Under sulfuric acid catalysis. (2) Under phosphoric acid catalysis. (3) Rearrangement pathways. 3.2 Hydride transfer reduction-rearrangement of cis-exo-2, 3-trimethylene-endo-2-hydroxymethylnorbornane (exo-34). 4. Preparative aspects of tricycloundecane rearrangement. 5. Conclusion. References.
