The first total synthesis and absolute structure assignment of PD-116740 (2) was achieved by exploiting two key steps: 1) a thermal ring expansion of a benzocyclobutene derivative, and 2) pinacol cyclization of biaryl dialdehyde.
A new approach was developed to achieve the asymmetrictotalsynthesis of (+)-PD-116740, an angucyclinone from the actinomycete isolate (WP 4669). A sequence of asymmetric dihydroxylation followed by oxidative cyclization was applied to stereoselectively construct the core trans-9,10-dihydrophenanthrene-9,10-diol B–C–D ring. A new Cu salt Cu(OH)OTf·NMI2 was found to be the best oxidant to induce the