Efficient and highly enantioselective formation of the all-carbon quaternary stereocentre of lyngbyatoxin A

Abstract

Indole 25, an advanced intermediate in a projected enantioselective total synthesis of lyngbyatoxin A 1, was prepared from allylic alcohol 11 in 9 steps and >95% ee, key transformations being the enantiospecific rearrangement of vinyl epoxide 14 and the Hemetsberger–Knittel reaction of azide 24.