Reactions of Pyridine Analogues of Aza-o-xylylenes Generated from 1,3-Dihydroisothiazolo[4,3-b]pyridine 2,2-Dioxides (Pyridosultams)-Formation of 2:1 Adducts with N-Phenylmaleimide

摘要

Pyridine analogues 16-20 of aza-o-xylylenes, generated from pyridosultams 11-15, enther inot Diels-Alder reactions with dienophiles to form 1,2,34-tetrahydronaphthyridines 23-28, which then add another equivalent of a dienophile to form 2:1 adducts 29-36. Intramolecular Diels-Alder reactions of aza-o-xylylenes 45 and 46, generated from pyridosultams 43 and 44, produced tricyclic pyrrolo-and pyridonaphthyridines 47 and 48, which were used for the constructruction of the 10,14-diazasteroid frameworks 52 and 54.