Model Studies Toward the Enantioselective Synthesis of Perhydrohistrionicotoxin: A Free-Radical Approach to the Azaspirocycle Core

Abstract

A free-radical-based protocol for the construction of the azaspirocyclic core of the natural product perhydrohistrionicotoxin is described. The adopted strategy is based on the use of an enantiomerically pure allylamine bearing a properly substituted cyclohexane at the allylic position as a radical acceptor. An unexpected reductive atom transfer radical addition reaction, followed by lactamization and removal of the chiral auxiliary is achieved in a single manipulation.

Key words

azaspirocyclic - atom transfer radical addition (ATRA) - perhydrohistrionicotoxin - Ellman sulfinyl imines - reductive ATRA reaction

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