Xylochemical Synthesis and Biological Evaluation of the Orchidaceous Natural Products Isoarundinin I, Bleochrin F, Blestanol K, and Pleionol.

The first total syntheses of the orchid-derived natural products isoarundinin I ( 1 ), (±)-bleochrin F ((±)- 2 ), (±)-blestanol K ((±)- 3 ), and (±)-pleionol ((±)- 4 ) from renewable starting materials are reported, along with the evaluation of their biological activities. The total syntheses were based on regioselective aromatic bromination reactions in combination with a key acid-promoted regioselective intramolecular cyclization. The biological results suggest that isoarundinin I ( 1 ), (±)-blestanol K ((±)- 3 ), and (±)-pleionol ((±)- 4 ) have the potential to inhibit the growth of both sensitive and multidrug-resistant cancer cells.