Bicyclo[3.3.1]nonanes as Synthetic Intermediates. XXIII.¹ A Breakthrough by Lanthanoid Mediation in Nucleophilic Addition of Carbanions to the Inert “Fork Head” Carbonyl in Bicyclo[3.3.1]nonan-3-ones

Abstract

Owing to the “backside steric hindrance”, the ‘fork head ketone’ (C-3 ketone) in bicyclo[3.3.1]nonan-3-ones is quite inactive against a nucleophilic attack of several kinds of organometallic reagents. Organocerium reagents and samarium iodide / organohalides turned out to react with the fork head ketone to afford the corresponding adducts efficiently.

Notes

The previous paper entitled “A Facile Synthesis of 7-Methylenebicyclo[3.3.1]-nonan-3-one and Its Transformation Leading to the Novel Tricyclic System, Protoadamantane” [Muraoka, O., Wang, Y., Okumura, M., Nishiura, S., Tanabe, G., and Momose, T., Synth. Commun., 1996, 26, 1555] constitutes Part XXII of this series. Part XXI: Momose, T., Toyooka, N., and Jin, M., J. Chem. Soc., Perkin Trans. 1, accepted.