The potential of the oxy-Favorskii rearrangement to form branched cis-fused bicyclic ethers was explored. Both tertiary and quaternary centers were constructed in highly stereospecific manners. Methanol and primary amines were effective nucleophiles for the rearrangement. The total synthesis of (±)-communiol E was achieved based on this method.
Stereochemical studies. XI. Equilibria between δ-hydroxy-acids and δ-lactones in aqueous tetrahydrofuran. Relative stabilities of isomeric δ-lactones
作者:John T. Edward、Ellen Cooke、Themistocles C. Paradellis
DOI:10.1139/v82-367
日期:1982.10.15
equilibrium constants K′ for the hydrolysis of 13 δ-lactones to hydroxy-acids in 54% (mol/mol) aqueous tetrahydrofuran at 25 °C have been determined. The equilibrium constants for the isomerization of the five δ-lactones into their epimers, and for the isomerization of their hydroxy-acids into their epimers, have been calculated by the methods of conformational analysis. These calculated values are consistent
Stereochemical editing logic powered by the epimerization of unactivated tertiary stereocenters
作者:Yu-An Zhang、Vignesh Palani、Alexander E. Seim、Yong Wang、Kathleen J. Wang、Alison E. Wendlandt
DOI:10.1126/science.add6852
日期:2022.10.28
The stereoselective synthesis of complex targets requires the precise orchestration of chemical transformations that simultaneously establish the connectivity and spatial orientation of desired bonds. In this work, we describe a complementary paradigm for the synthesis of chiral molecules and their isomers, which tunes the three-dimensional structure of a molecule at a late stage. Key to the success