Recently, a significant research breakthrough was made by the research team led by Jingjing Wu at Shanghai Jiao Tong University. Their work which is entitled " Photocatalytic Stereochemical Editing for the Concise Syntheses of (25S)-Δ⁷-Dafachronic acid, Demissidine and Smilagenin" has been officially published in the prestigious journal Angew

Article abstract:

Figure 1:The structures of (25S)-Δ⁷-dafachronic acid (1), desmissidine (2), and smilagenin (3), along with the currently developed synthetic strategies.

Stereochemistry editing serves as an important tool to precisely adjust the desired stereochemical configuration of a molecule. In this study, enabled by photocatalytic stereochemical editing of tertiary C─H bonds of steroids, we have completed concise syntheses of (25S)-Δ⁷-dafachronic acid, demissidine, and smilagenin. The feasibility of regioselectively editing tertiary stereocenters with either very weak α-hydroxyl C─H bonds (in the synthesis of dafachronic acid), α-amino C─H bonds (in the synthesis of demissidine), or with varying steric hindrance (in the synthesis of smilagenin) has been successfully demonstrated.