Sa. Molchanov et al., Thermolysis of the esters of substituted 3,7-triazabicyclo[3.3.0]oct-3-ene-4-carboxylic acids, RUSS J ORG, 36(6), 2000, pp. 899-903
Heating to 190-200 degreesC of the esters of substituted 2,3,7-triazabicycl
o[3.3.0]oct-3-ene-4-carboxylic acids afforded esters of 3-azabicyclo[3.1.0]
hexane-6-carboxylic acids as a mixture of exo and endo isomers. The reactio
n carried out in chlorobenzene at 130 degreesC in the presence of copper st
earate yielded only exo isomers.