An azomethine ylide approach to complex alkaloid-like heterocycles.
The nitrone above is readily available via the intramolecular aza Diels-Alder reaction of an amino acid derived triene in acetic acid. Subsequent treatment of the nitrone in refluxing toluene with substituted actetylenes produced the pictured pyrrole. At lower temperatures a 2,3-dihydroisoxazole, which is the product of a 3+2 dipolar cycloaddition, is produced. Upon heating in refluxing toluene the 2,3-dihydroisoxazole is converted to the pyrrole.
Murray
William V
WV
Johnson and Johnson Pharmaceutical Research and Development LLC, 8 Clarke Drive, Cranbury, New Jersey 08512, USA. wmurray@prdus.jnj.com
Francois
David
D
Maden
Amy
A
Turchi
Ignatius
I
D000470:Alkaloids / Q000737:chemistry*; D001391:Azo Compounds / Q000737:chemistry*; D006576:Heterocyclic Compounds, 4 or More Rings / Q000737:chemistry*; D015394:Molecular Structure; D011758:Pyrroles / Q000138:chemical synthesis / Q000737:chemistry; D013882:Thiosemicarbazones / Q000737:chemistry*
D000470:Alkaloids; D001391:Azo Compounds; D006576:Heterocyclic Compounds, 4 or More Rings; D011758:Pyrroles; D013882:Thiosemicarbazones; C512188:azomethine