BF3*OEt2 catalyzed synthesis of spiropyrrolidine frameworks via (3, 5)-oxonium-ene cyclization. (28th September 2022)

• Record Type: Journal Article
• Authors: Prudhvi Raju, N.; Jagan Mohan Reddy, B.; Rasvan Khan, P.; Aita, Saikiran; Jithender Reddy, G.; Sridhar, B.; Subba Reddy, B.V.
• Is Part Of: Tetrahedron letters. Volume 107(2022)
• Publication Date: 2022-09-28
• Subjects: Lewis acid -- Oxonium-ene cyclization -- Aldehydes -- γ-hydroxyalkene -- Spiropyrrolidine; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2022.154101
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Highlights: First report on spiropyrrolidine by Prins cyclization. Catalyst is readily available at low cost. Mild reaction conditions. Short reaction times. Abstract: γ-Hydroxyolefin derived from proline undergoes a smooth ene cyclization with aldehydes to produce the 7-oxa-1-azaspiro[4.5]decane scaffolds in good yields. Whereas the condensation of γ-hydroxyalkene with 2-hydroxybenzaldehyde affords the corresponding tetrahydro-2 H -spiro[pyrano[3, 2- c ]chromene-3, 2′-pyrrolidine derivatives in excellent yields. This is the first report on the ene cyclization of aldehydes with γ-hydroxyalkene derived from the α-amino acid, proline.