The structure of a novel ecdysteroid, gerardiasterone, is elucidated as 2a by its synthesis employing a diastereoselective dihydroxylation of the E-olefin 22 as a key step.
The first synthesis of a newzooecdysteroidgerardiasterone was achieved in a diastereoselective manner employing asymmetric dihydroxylation of the E-olefin 34 in the presence of DHQ-CLB as a chiral ligand. This synthesis unambiguously confirmed the structure of gerardiasterone as (20R,22R,23S)-2β,3β,14α,20,22,23,25-heptahydroxy-5β-cholest-7-en-6-one (2a).