1-Alkoxycarbonylalkylidenetriphenylarsoranes: Preparation and reactions
摘要:
The higher homologues of the well-studied alkoxycarbonylmethylenetriphenylarsonium(1) ylide (3, R=H) can be easily obtained through the sequence: a). preparation of alkyl 2-trifloxyalkanoates (1); b), reaction between these trifloxyderivatives and triphenylphosphine to give 1-alkoxycarbonylalkyltriphenylarsonium triflates (2); and c), basic treatment of the triphenylarsonium triflates (2) with alumina-supported potassium fluoride to give 1-alkoxycarbonylalkyledenetriphenylarsonium ylides (3). These higher homologues of(3, R=H) react with aromatic aldehydes in good to excellent yields. and give rise to synthetically interesting ''coupling'' and cyclopropanation reactions.