Catalytic Enantioselective [4+2] Cycloadditions of Salicylaldehyde Acetals with Enol Ethers
Xiaojun Hu, Zhengbo Zhu, LI Zhong-zheng, Alafate Adili, Minami Odagi, Khalil A. Abboud, Daniel Seidel
Abstract
A readily accessible conjugate-base-stabilized carboxylic acid (CBSCA) catalyst facilitates highly enantioselective [4+2] cycloaddition reactions of salicylaldehyde-derived acetals and cyclic enol ethers, resulting in the formation of polycyclic chromanes with oxygenation in the 2- and 4-positions. Stereochemically more complex products can be obtained from racemic enol ethers. Spirocyclic products are also accessible.
Topics & Concepts
Enantioselective synthesisEnolSalicylaldehydeChemistryCatalysisCycloadditionOrganic chemistryConjugateStereochemistrySchiff baseMathematical analysisMathematicsSynthesis of Indole DerivativesAsymmetric Synthesis and CatalysisAxial and Atropisomeric Chirality Synthesis