The Structural Revision and Total Synthesis of Carambolaflavone A

The
synthesis of both enantiomers of carambolaflavone A, the antidiabetic
and flavonoid C-glycoside, was achieved for the first
time via a 12-longest-linear-step with 16% (l-fucose) and
11% (d-fucose) overall yields. Through the synthetic investigation,
the adverse effect of 4A MS in Suzuki C-glycosylation
was disclosed, the mechanism of hydrogen-bonded-phenol involved Suzuki C-glycosylation was clarified, and the authentic structure
of carambolaflavone A was also determined.