An asymmetric synthesis of (S)-(-)-deplancheine has been achieved in 96.5% ee via the chiral valine-based formamidine 8 of P-carboline. Alkylation of the latter, via its lithio salt, with the appropriate alkyl bromide 19c gave the highly enantioenriched intermediate 20, which was carried forward to the title product. On the basis of the stereochemical properties of deplancheine, the original assignment of absolute configuration (S) has now been ...
