Related Experiment Video
Updated: May 24, 2026

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
Reactivity of bispropargyl sulfones under basic conditions: interplay between Garratt-Braverman and
Raja Mukherjee1, Sayantan Mondal, Amit Basak
1Department of Chemistry, Indian Institute of Technology, Kharagpur 721 302, India.
Abstract:
The preference for Garratt-Braverman (GB) over Myers-Saito (MS) and Schmittel (SCM) cyclizations has recently been demonstrated in sulfones capable of undergoing all three of the processes. As the GB cyclization is a self-quenching process, there is a need to change the selectivity to the non-self-quenching MS or SCM pathway so as to enhance the DNA-cleaving efficiency that operates through the radical-mediated process. Herein we report a conformational constraint-based strategy developed by using computations (M06-2X/6-31+G*) to switch the selectivity from GB to MS/SCM pathway which also results in greater DNA-cleavage activity. The preference for GB could be brought back by easing the constraint with the help of spacers.
More Related Videos
Related Concept Videos
Preparation and Reactions of Sulfides
Radical Substitution: Allylic Bromination
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.
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
SN2 Reaction: Stereochemistry
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not observed.
Electrophilic Aromatic Substitution: Sulfonation of Benzene

