Reaktionen mesoionischer Fünfringheterocyclen mit o-chinoiden Verbindungen, V [1, 2]. 1.3-Oxazolium-5-olate und 1.3-Thiazolium-5-olate / Reactions of Five-Membered Mesoionic Heterocycles with o-Quinonoid Compounds, V [1, 2] 1,3-Oxazolium-5-olates and 1,3-Thiazolium-5-olates

Abstract

1,3-Oxazolium-5-olates (1) 1,3-thiazolium-5-olates (11) react with o-benzoquinones (3) and α-naphthoquinone to give adducts (4, 5, 6, 15) which can formally be derived from ketone valence tautomers of 1 and 11. 9,10-Phenanthrenequinone and 1 a yield a compound (10) which possibly results from an initially formed [π4 + π4] adduct (7) with subsequent loss of CO2. Consistent with this view is a product (14) of the reaction between 9,10-phenanthrenequinone and 11. The structure of 14 has been determined by X-ray crystallography