7r-Route

The second route to 2,4-disubstituted adamantanes involves a 7r-route ring closure of substituted bicyclo[3.3.1]nonenes. Thus, lactone 85 28S) rearranges in 50 % sulfuric acid to 4-hydroxy-2-adamantanone (86) via the acylium ion 87 278>. Adamantanone oxime rearranges in 96 % sulfuric acid to 86 (mixture of isomers) in an analogous manner 109h Similarly, the Schmidt reaction of... 

The driving force for these 7r-route ring closures is large. In 80 % acetone, the solvolysis of the unsaturated tosylate 89 is 104 times faster than that of the sa-... 

The 5-methyl derivatives of (816) and (818) have been generated by the 7r route from (824) and (827), respectively557. The results are very similar to those of the parent system. Again, there is more leakage from (825) to (826) than in the reverse direction. 

Coates and Bertram developed a 7r-route to usefully substituted compounds potentially convertible by the acyl azide procedure" to atisine derivatives. Iso-steviol (70) was converted to the unsaturated tosylate (71). Buffered formolysis... 

---