Diastereoselective pictet-spengler reactions of L-(boc)prolinal: a biomimetic synthesis of eudistomins H and I, and woodinine

The carbon skeleton present in eudistomins H, I and in woodinine may be envisioned to be biosynthetically derived from tryptamine and L-prolinal by a Pictet-Spengler type reaction. The diastereoselectivity (5:1) of this reaction, and the elaboration of the Pictet-Spengler products into the title compounds is described. The absolute stereochemistry of (−) woodinine is thereby established.