Singh G, Gupta N, Sethi N, Gupta V, Raj T, Ishar MPS. Facile Synthesis of Some New Peptidomimetic β
3 -and β
2,3 -Amino Alcohols Possessing Pyridyl Moiety via Reductive Ring Opening of Pyridyl-isoxazolidines.
Chem Biodivers 2024;
21:e202301323. [PMID:
38116925 DOI:
10.1002/cbdv.202301323]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 11/21/2023] [Accepted: 12/18/2023] [Indexed: 12/21/2023]
Abstract
Regio- and stereoselective 1,3-dipolar cycloadditions of C-(3-pyridyl)-N-phenylnitrone (2) with variedly substituted dipolarophiles (3, 4) were carried out to obtain substituted pyridyl-isoxazolidines (5-8). Reductive cleavage of pyridyl-isoxazolidines (5-8) with ammonium formate, methanol-THF solvents, at ambient temperature, in the presence of Pd/C provided a facile route for the synthesis of β3 -and β2,3 -amino alcohols (9-12), with a substitution pattern having pronounced influence on torsional angles. The obtained compounds (9-12) are valuable scaffolds which can be utilized for peptidomimetics. Thus, the present methodology for reductive opening of isoxazolidine ring avoids the disadvantages of using expensive apparatus and hazards involved in the use of hydrogen gas. The preferential formation of amino-alcohols in case of bicyclic isoxazolidines (8a-c), which precludes any recyclization is rationalized by DFT calculations.
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