New cyclic aminals derived from rac-trans-1,2-diaminocyclohexane: synthesis and crystal structure of racemic 1,8,10,12-tetraazatetracyclo[8.3.1.1.8,1202,7] pentadecane and a route to its enantiomerically pure (R,R) and (S,S) isomers
作者
Augusto Rivera,Diego Quiroga,Leonardo Jiménez-Cruz,Karla Fejfarová,Michal Dušek