An aza-Wittig/pi-furan cyclization approach toward the homoerythrina alkaloid (+/-)-selaginoidine.
[reaction: see text] A one-pot procedure was developed to efficiently prepare hexahydroindolinones containing a tethered furan ring. Reaction of a furanyl azide with Bu3P delivered the iminophosphorane, which was allowed to react with 1-methyl-(2-oxocyclohexyl)acetic acid to give the desired hexahydroindolinone ring system. Further treatment with trifluoroacetic acid afforded the tetracyclic lactam skeleton found in the alkaloid (+/-)-selaginoidine.
Cassidy
Michael P
MP
Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA.
Ozdemir
Ayse Daut
AD
Padwa
Albert
A
D003500:Cyclization; D005663:Furans / Q000138:chemical synthesis / Q000737:chemistry*; D006576:Heterocyclic Compounds, 4 or More Rings / Q000138:chemical synthesis*; D026121:Indole Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010946:Plants, Medicinal / Q000737:chemistry; D013237:Stereoisomerism
D005663:Furans; D006576:Heterocyclic Compounds, 4 or More Rings; D026121:Indole Alkaloids; C506850:selaginoidine