[1,3]-Claisen Rearrangement via Removable Functional Group Mediated Radical Stabilization
Md Nirshad Alam, Soumya Ranjan Dash, Anirban Mukherjee, Satish Pandole, Udaya Kiran Marelli, Kumar Vanka, Pradip Maity
Abstract
A thermal O-to-C [1,3]-rearrangement of α-hydroxy acid derived enol ethers was achieved under mild conditions. The 2-aminothiophenol protection of carboxylic acids facilitates formation of the [1,3] precursor and its thermal rearrangement via stabilization of a radical intermediate. Experimental and theoretical evidence for dissociative radical pair formation, its captodative stability via aminothiophenol, and a unique solvent effect are presented. The aminothiophenol was deprotected from rearrangement products as well as after derivatization to useful synthons.
Topics & Concepts
ChemistrySynthonClaisen rearrangementCarroll rearrangementEnolDerivatizationRadical cyclizationFunctional groupRearrangement reactionProtecting groupSigmatropic reactionCarboxylic acidPhotochemistryCombinatorial chemistryOrganic chemistryCatalysisPolymerHigh-performance liquid chromatographyAlkylRadical Photochemical ReactionsAdvanced Synthetic Organic ChemistryAsymmetric Synthesis and Catalysis