Ss. Koval'Skaya et al., Synthesis and Ritter reaction of endo-2-ethynyl-1,7,7-trimethyl- and exo-2-ethynyl-5,5,6-trimethylbicyclo[2.2.1]heptan-2-ols, RUSS J ORG, 36(3), 2000, pp. 379-385
endo-2-Ethynyl-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol and exo-2-ethynyl-5
,5,6-trimethylbicyclo[2.2.1]heptan-2-ol were obtained by treatment of 1,7,7
-trimethylbicyclo[2.2.1]heptan-2-one and 5,5,6-trimethylbicyclo[2.2.1]hepta
n-2-one, respectively, with lithium acetylide. The reaction of endo-2-ethyn
yl-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol with acetonitrile in the presen
ce of sulfuric acid (Ritter reaction) is accompanied by a series of skeleta
l rearrangements resulting in formation of exo-2-acetylamino-4-ethynyl-1,7,
7-trimethylbicyclo[2,2.1]heptane with a small admixture of 4-acetyl-exo-2-a
cetylamino-4-ethynyl-1,7,7-trimethylbicyclo[2.2.1]heptane. The Ritter react
ion of exo-2-ethynyl-5,5,6-trimethylbicyclo[2.2.1]heptan-2-ol yields a 1:1
mixture of endo-6-acetyl-exo-2-acetyiamino-1,7,7-trimethylbicyclo[2.2,1]hep
tane and 2-acetyl-exo-2-acetylamino-5,5,6-trimethylbicyclo[2.2.1]heptane.