Serinolic Amino‐ s ‐triazines: Iterative Synthesis of N ‐Substituted Amino‐1,3‐dioxane Derivatives from l ‐( p ‐Nitrophenyl)serinols and Rotational Stereochemistry Phenomena

We report the first iterative and chemioselective approach towards the synthesis of highly elaborated N ‐substituted 2,4,6‐triamino‐ s ‐triazines (melamines) and precursors, by amination of cyanuric chloride with anancomeric and enantiomerically pure primary and tertiary amino‐1,3‐dioxanes. The starting nucleophiles were prepared by direct diastereospecific and diastereoselective acetalization of N ‐substituted (1 S ,2 S )‐2‐amino‐1‐( p ‐nitrophenyl)propane‐1,3‐diols [ l ‐( p ‐nitrophenyl)serinols]. The stereochemistry of the title compounds is discussed in terms of (pro)diastereomerism originating from restricted rotation about the newly created C( s ‐triazine)–N< bonds and supported by NMR and DFT calculation data.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)