Synthesis of ent-alantrypinone.
This paper presents a synthesis of ent-alantrypinone (ent-6), the enantiomer of a natural product produced by the fungus Penicillium thymicola. The synthesis revolves around the Li[Me(3)AlSPh]-promoted isomerization of iminobenzoxazine 33 to quinazolinone 34, an N-acyliminium ion cyclization that converts enamide 9 to bridged indole 35, and rearrangement of 35 to oxindole ent-6. Ancillary chemistry that involves thermal fragmentation of an iminobenzoxazine to a nitrile ylide and Me(2)AlSPh-mediated cyclization of oxime ether-ester 22 to pyrrolidinone 23 is also described.
Hart
D J
DJ
Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210, USA.
Magomedov
N A
NA
D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D007202:Indicators and Reagents; D007211:Indoles; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D010407:Penicillium / Q000378:metabolism; D011799:Quinazolines; D013237:Stereoisomerism
D000470:Alkaloids; D007202:Indicators and Reagents; D007211:Indoles; D011799:Quinazolines; C115545:alantrypinone