Total syntheses of the dibenzocyclooctadiene natural product
wuweizisu C in its (-)-form [(S)-1] and its (+)-form [(R)-1] were
achieved in 19 steps, starting from commercially available gallic
acid. In the key step, the asymmetric biphenyl axis was constructed
by an oxazoline-mediated Ullmann reaction to provide either the P or M biaryl
product in 68% yield and >99% de, depending on
the configuration of the oxazoline. The efficiency of this total synthesis
was excellent, as the syntheses of (S)-1 and (R)-1
from intermediate 7 each proceeded in 13 steps with an overall
yield of 6.8%. (S)-1 and (R)-1 were evaluated as chemosensitizers for
multidrug-resistant cancers.
wuweizisu C - stereoisomer - asymmetric synthesis - biaryls - multidrug resistance
- p-glycoprotein
