Dedicated to the memory of the late Professor Sho Ito
Published as part of the 50 Years SYNTHESIS – Golden Anniversary Issue
Abstract
A general synthetic approach to rotenoids is described, featuring 1) stereospecific, group-selective 1,2-rearrangements of epoxy alcohols, and 2) SNAr oxy-cyclizations of aryl fluorides. The common intermediate epoxyketone, en route to (–)-rotenone and (–)-deguelin, was prepared from d-araboascorbic acid in five steps. Also described is the conversion of (–)-deguelin into oxidized congeners, (–)-tephrosin and (+)-12a-epi-tephrosin.
Key words
isoflavonoid - rotenoid - semi-pinacol rearrangement - S
NAr cyclization - total synthesis