Ring Opening Reactions of 3-Phosphonocoumarin Under Michael Reaction Conditions

Computational elucidation of the reaction mechanism for synthesis of pyrrolidinedione derivatives via Nef-type rearrangement – cyclization reaction

“…The whole reaction mechanism involves three main stages depending on the type of reactions (for notation of structures and numbering of the atoms see Scheme 1 and Section 4): 1,2 2.1. Michael addition reaction of CH 3 NO 2 to the C4 carbon atom of the coumarin (Fig.…”

“…Michael addition followed by a Nef-type rearrangement reaction (Scheme 1) in which coumarin derivatives 1 are transformed into pyrrolidinedione products 8, 1-hydroxy-4-(2-hydroxyphenyl)-2,5-dioxopyrrolidine was reported to occur with an excellent yield. 1,2 Initially the reaction was reported with 3-phosphonocoumarin, but later we showed that this rearrangement reaction occurs also with other 3-substituted coumarins and the coumarin itself as reactants 2 and can nd application in the target synthesis of 3,4-disubstituted pyrrolidine derivatives with potential biological activity.…”

A New and Efficient Method for the Synthesis of 3,4-Disubstituted Pyrrolidine-2,5-diones

“…Recently, a new rearrangement reaction was reported [24] (Scheme 1) in which 3-phosphonocoumarin 1 has been transformed into the new product 1-hydroxy-4-(2′-hydroxyphenyl)-2,5-dioxopyrrolidine-3-yl-phosphonate ( 2 ) in excellent yield.…”

“…In these investigations the best reaction conditions for the preparation of pyrrolidines were applied [24]. It was surprising that in the case of 2-oxo-2 H -chromene-3-carbonitrile 45% of the substrate was recovered and the yield of pyrrolidine derivative was only 17%.…”

Synthesis and Chemical Properties of 3-Phosphono-coumarins and 1,2-Benzoxaphosphorins as Precursors for Bioactive Compounds

“…The interaction between coumarin 1a and nitromethane using different bases (KF, Et 3 N, C 5 H 11 N) in a protic solvent (EtOH) led to formation of compounds 45 and 46 (Scheme 33, Method B) [58]. Product 45 was isolated in an overall yield of 74% as a mixture of two trans -isomers in 1:1.25 ratio when potassium fluoride was used as a base.…”