Related Experiment Video
Updated: May 10, 2026

Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy
Published on: November 9, 2019
Highly stereoselective synthesis of 2,6-cis-substituted tetrahydropyrans using a one-pot sequential catalysis
Qipu Dai1, Nirmal K Rana, John Cong-Gui Zhao
1Department of Chemistry, University of Texas at San Antonio , One UTSA Circle, San Antonio, Texas 78249-0698, United States.
Abstract:
A catalytic highly diastereo- and enantioselective synthesis of 2,6-cis-substituted tetrahydropyrans was realized using a one-pot sequential catalysis involving Henry and oxa-Michael reactions. The nitroaldol products obtained in a highly enantioselective copper(II)-catalyzed Henry reaction between nitromethane and 7-oxo-hept-5-enals were subsequently treated with a catalytic amount of camphorsulfonic acid (CSA) to give the desired tetrahydropyran derivatives in excellent yields, diastereoselectivities (dr >99:1), and enantioselectivities (ee = 98-99%). The reaction can also be used for the high stereoselective synthesis of a cis-2,6-disubstituted morpholine.
More Related Videos
10:17Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
07:56Preparation of 6-aminocyclohepta-2,4-dien-1-one Derivatives via Tricarbonyl(tropone)iron
Published on: August 12, 2019
Related Concept Videos
Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Regioselectivity and Stereochemistry of Hydroboration
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
Thermal Electrocyclic Reactions: Stereochemistry
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Thermal and Photochemical Electrocyclic Reactions: Overview
Cycloaddition Reactions: Overview