Affiliation:
1. Department of Chemistry, Faculty of Science, Shree Guru Gobind Singh Tricentenary University, Gurugram 122505,
Haryana, India
Abstract
Abstract:
The steroidal B-ring 2H-pyran 2 is synthesized by reacting steroidal B-ring α,β-
unsaturated ketone 1 and 2-cyano-N-methylacetamide by refluxing for 18 h in methanol in the presence
of a catalyst, i.e., chitosan. The product is obtained with a yield of 67%. The structure of the
final product 2 is confirmed by utilizing IR, Mass, 13C and 1H NMR spectra. The reaction
mechanism of the steroidal pyran ring formation is explored in this paper. The reaction pathway is
described by using FMO analysis and relative energies of starting material, intermediate, and
transition states, calculated by using the theoretical method, i.e., DFT with B3LYP/6-31G(d). It is
found that two intermediates are formed throughout the reaction, which undergo a respective
transition state (TS1 and TS2). The energy barrier of each step of the reaction is also calculated. It is
also concluded that the reaction is endothermic. The green synthetic method reported in this study
would be very useful for the synthetic and medicinal chemists involved in the synthesis of biologically
important pyran ring-containing heterocyclic compounds.
Publisher
Bentham Science Publishers Ltd.