1,3-versus 1,4-[(pi)4+(pi)2] Cycloadditions between methyl glyoxylate oxime and cyclopentadiene or cyclopentene

• Type: Article in International Scientific Journal
• Date: 2012

Authors

Carlos A D Sousa (Author) Other; Luisa L C Vale (Author) FCUP; Xerardo Garcia Mera (Author) Other; Jose E Rodriguez Borges (Author) FCUP

Journal

Title: Tetrahedron

Vol. 68

Pages: 1682-1687

ISSN: 0040-4020

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 17 Citations

Scopus - 18 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-002-D2C

DOI: 10.1016/j.tet.2011.12.073

Abstract (EN): The acid catalyzed cycloaddition reaction of methyl glyoxylate oxime with cyclopentadiene (CPD) afforded the corresponding aza-Diels-Alder adducts, the endo and exo isomers of (+/-)-methyl 2-hydroxy-2-azabicyclo[2.2.1]hept-5-ene-3-carboxylates, and as the major product a 1,3-cycloadduct, methyl (1RS,4RS,5RS)-(2-oxa-3-azabicyclo[3.3.0]oct-7-ene)-4-carboxylate. The similar reaction using cyclopentene (CP) provided only the 1,3-cycloadduct methyl (1SR,4RS,5SR)-(2-oxa-3-azabicyclo[3.3.0]octane)4-carboxylate. The influence of various parameters on the reaction outcome was studied and, based on the results obtained, a mechanism for the formation of both 1,3- and 1,4-cycloadducts is proposed. The structure of all adducts was confirmed by NMR spectroscopic data and/or by X-ray crystallography.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6