NMR spectroscopic and theoretical structural analysis of 5-benzyl substituted hydantoins in solution

The vicinal H,H and H,C coupling constants along the Ph-CH2AB-CRHM-C-X(=O)R ' spin system of 5-benzyl substituted hydantoins together with the results of accompanying force field (TRIPOS) and quantum chemical ab initio calcula tions (GAUSSIAN-94 with atomic basis set of 3-21G type) were employed to re port on the rotamer population about the hydantoin C(5)-benzyl substituent bond. The conformation having the phenyl ring folded over the hydantoin rin g system proved to be preferred. (C) 1999 Elsevier Science B.V. All rights reserved.