Deelertpaiboon P.Kongsriprapan S.Krajangsri S.Betterley N.M.Kuhakarn C.Reutrakul V.Mahidol University2023-06-182023-06-182022-07-01Synthesis (Germany) Vol.54 No.13 (2022) , 3093-310400397881https://repository.li.mahidol.ac.th/handle/123456789/84182The asymmetric synthesis of the novel pyranonaphthoquinones ventilanone A and ventilanone B, isolated from the Thai endemic plant Ventilago harmandiana, is accomplished by employing L-rhamnose and gallic acid as the starting materials. The key reactions are the utilization of a newly introduced reagent, PhSCF2H/SnCl4, for the formylation of sterically hindered aromatics containing an electron-withdrawing methyl ester, and the efficient Hauser annulation of phenylthiophthalides with optically active C-1 glycals derived from L-rhamnose. The developed synthetic methodologies solve the long-standing problem of the formylation of sterically hindered aromatics containing electron-withdrawing groups, and are applicable for the synthesis of other analogues with substituents on the aromatic and pyran rings.ChemistryArticleSCOPUS10.1055/a-1773-43862-s2.0-851288366201437210X