Synthesis of anatoxin a via intramolecular cyclization of iminium salts

Journal Article · Tue Feb 27 23:00:00 EST 1979 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00499a035· OSTI ID:6377651

Bates, H A; Rapoport, H

Anatoxin a (1) has been synthesized by exploiting intramolecular cyclization between an iminium salt and a nucleophilic carbon to construct the 9-azabicyclo(4.2.1)nonane ring system. Cyclization of malonate iminiumsalt 16 at alkaline pH afforded a low yield of bicyclic malonate 18 owing to an unfavorable equilibrium constant and lability of the iminium salt in base. In contrast, cyclization of ketoiminium salt 31 afforded a good yield of bicyclic ketone 34 in acidic methanol. Dihydropyrrolium salts 16 and 31 were generated quantitatively by decarbonylation of substituted N-methylprolines 15 and 30b, obtained by reduction of the corresponding pyrroles.

• Research Organization: Univ. of California, Berkeley
• OSTI ID: 6377651
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 101:5; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ALKALOIDS
CARBOXYLIC ACIDS
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
DICARBOXYLIC ACIDS
IMINES
MALONIC ACID
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PH VALUE
SALTS
SYNTHESIS
YIELDS