New supramolecular host systems, 11. The stereoisomeric diaminobutanediol and dioxadiazadecalin systems: Synthesis, structure, stereoelectronics, and conformation - Theory vs. experiment

We present new approaches to the (C₂) chiral and meso 1,4-diamino-2,3- butanediol (1) and 2,3-diamino-1,4-butanediol (2) and derivatives. Reactions of these compounds with aldehydes to form the novel 1,5-dioxa-3,7- diazadecalin (DODAD) and 1,5-diaza-3,7-dioxadecalin (DADOD) classes of compounds (7, 9, 11-15) are also reported. These reactions are diastereospecific, i e, erythro (meso) or threo starting compounds lead to trans or cis products, respectively. The structural, conformational, and stereoelectronic aspects of these systems were probed experimentally and computationally and provided excellent insight into their properties and behaviour. Good agreement was observed between X-ray, NMR, and calculated results of the N,N'-dibenzyl derivatives of trans-DODAD (14) and trans-DADOD (15).