Synthesis of the tetracyclic ABCD ring systems of madangamines D-F
Synthesis of the tetracyclic cores of madangamines D-F was achieved, featuring a reductive radical process from an ethoxycarbonyldichloroacetamide to build the morphan nucleus, a Mitsunobu-type aminocyclization toward the common diazatricyclic intermediate, and ring-closing metathesis reactions for the macrocyclization step leading to the 13- to 15-membered rings.
A New Method to Generate α-Aminoalkyl Radicals: Treatment of Methyl α-Amino Selenoesters with Hydride Reagents. Synthesis of 6-Azabicyclo[3.2.1]octanes by Radical Cyclization
A new method to generate α-aminoalkyl radicals and its application to the synthesis of 6-azabicyclo[3.2.1]octanes is described. α-Amino selenoesters on heating with Bu3SnH or (Me3Si)3SiH undergo decarbonylation of the initially formed acyl radical to give the corresponding α-amino radical which could be trapped intramolecularly with a double bond bearing an electron-withdrawing group.