A concise synthesis of the AE bicyclic system of Daphniphyllum alkaloid yuzurine is described. The synthetic sequence features a Dieckmann condensation to construct ring A, reduction of α, β-unsaturated double bond and propargylation of α-position of lactone to diastereoselectively generate relative stereocenter C-3, C-4 and C-5, and an acid-catalyzed cyclization to assemble ring E.Download high-res image (88KB)Download full-size image

A substrate stereocontrolled synthesis of the BCD tricyclic ring system of densanins A and B has been developed. The key transformations include the assembling of ring B via an unprecedented tandem N-allylation/SN2′ reaction and the construction of ring C via gold-catalyzed alkenylation of terminal alkyne and pyrrole.

This article reported an eight steps formal total synthesis of (−)-kainic acid in 16% overall yield from an enantiopure starting material. The key transformations include an efficient tandem N-allylation/SN2′ reaction to construct the 2,3-trans-3,4-cis tri-substituted pyrrolidine and a HgCl2-promoted methanolysis of 1,4-benzodithia-fulvene to furnish the ester group.This article reported an eight steps formal total synthesis of (−)-kainic acid from an enantiopure starting material. The key transformations include an efficient tandem N-allylation/SN2′ reaction to construct the 2,3-trans-3,4-cis tri-substituted pyrrolidine and a HgCl2-promoted methanolysis of 1,4-benzodithia-fulvene to furnish the ester group.