The Stabilizing Role of the Intramolecular C–H···O Hydrogen Bond in Cyclic Amides Derived From α‑Methylbenzylamine

A series of five-, six-, seven-,
and eight-membered lactams containing
the chiral auxiliary α-methylbenzylamine were structurally analyzed
and further studied by DFT calculations with the purpose to examine
with detail the previously detected intramolecular C–H···O
hydrogen-bonding interaction formed between the hydrogen atom of the
α-methylbenzylamine and the carbonyl group of the cyclic amide.
The main objective was to establish whether its presence does have
a tangible relevance in their spatial arrangement in solution and
in the solid state or is a simple and not stabilizing interaction.