Fully Substituted Carbon Centers by Diastereoselective Spirocyclization: Stereoselective Synthesis of (+)-Lepadiformine C

…, MD Morin, BW Slafer, SA Wolckenhauer…

Index: Perry, Matthew A.; Morin, Matthew D.; Slafer, Brian W.; Wolckenhauer, Scott A.; Rychnovsky, Scott D. Journal of the American Chemical Society, 2010 , vol. 132, # 28 p. 9591 - 9593

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Citation Number: 22

Abstract

Reductive lithiation of N-Boc α-amino nitriles generated α-amino alkyllithium reagents with unexpected selectivity. The intermediate radical prefers to align with the nitrogen lone pair, and this interaction leads to an A1, 3-strain effect that biases the conformation of the radical. In cyclohexane rings with α-substituents the net effect is an inversion of configuration on reductive lithiation. In the presence of a tethered electrophile the alkyllithium cyclizes to ...