Journal of the American Chemical Society, Vol.143, No.3, 1428-1434, 2021
Seven-Step Stereodivergent Total Syntheses of Punicafolin and Macaranganin
The first total syntheses of punicafolin (1) and macaranganin (2) were achieved in seven steps, respectively, from commercial alpha-D-glucose. The characteristic features of the synthesis are (1) sequential site-selective introduction of the adequate galloyl groups into unprotected D-glucose by a catalyst-controlled manner and (2) stereodivergent construction of the 3,6-HHDP bridge by oxidative phenol coupling of a common intermediate via a ring-flipping process of the glucose core. Because no protective groups were used for glucose throughout the process, extremely short-step total syntheses of natural glycosides 1 and 2 (MW 938) were performed.