Catalytic, Cascade Ring-Opening Benzannulations of 2,3-Dihydrofuran O,O- and N,O-Acetals was written by Aponte-Guzman, Joel;Phun, Lien H.;Cavitt, Marchello A.;Taylor, J. Evans Jr.;Davy, Jack C.;France, Stefan. And the article was included in Chemistry – A European Journal in 2016.Application In Synthesis of Ethyl 3-oxo-3-(thiophen-2-yl)propanoate This article mentions the following:
An Al(OTf)3-catalyzed intramol. cascade ring-opening benzannulation of 2,3-dihydrofuran O,O- and N,O-acetals was described. The cascade sequence involved the dihydrofuran ring-opening by acetal hydrolysis, an intramol. Prins-type cyclization, and aromatization to generate an array of benzo-fused (hetero)aromatic systems in up to 95 % yield. This method represented the first example of dihydrofuran acetal usage in benzannulation reactions. The approach provided excellent regiocontrol based on the choice of alkenes used to form the requisite dihydrofuran acetals. In the experiment, the researchers used many compounds, for example, Ethyl 3-oxo-3-(thiophen-2-yl)propanoate (cas: 13669-10-8Application In Synthesis of Ethyl 3-oxo-3-(thiophen-2-yl)propanoate).
Ethyl 3-oxo-3-(thiophen-2-yl)propanoate (cas: 13669-10-8) belongs to esters. Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits. Many esters have the potential for conformational isomerism, but they tend to adopt an s-cis (or Z) conformation rather than the s-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.Application In Synthesis of Ethyl 3-oxo-3-(thiophen-2-yl)propanoate
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics