Conformations of Azacyclodeca-3,8-diynes and 1,6-Diazacyclodeca-3,8-diynes and the Generalized Anomeric Effect: A Test for Current Conformational Models for Azaheterocycles

摘要

The preference of the axial orientation of the substituents on the nitrogen atom(s) in 4 and 5 is interpreted in terms of the vicinal interactions of both the NR bond and the lone pair with the adjacent CH and CC bonds, synaxial 1, 3-interactions of both the NR bond and the lone pair, and secondary interactions of CH/CC bonds of the alkyl substituent with the endocyclic CH_2 groups as well as with triple bonds (back and front strain).