Synthesis 2024; 56(07): 1157-1166
DOI: 10.1055/s-0042-1751505
paper
Emerging Trends in Glycoscience

Diastereoselective Synthesis of Carbohydrate Conjugates: Pyrano[3,2-c]quinolones

Sumit Kumar
a   Bioorganic Laboratory, Department of Chemistry, University of Delhi, Delhi-110 007, India
,
Aditi Arora
a   Bioorganic Laboratory, Department of Chemistry, University of Delhi, Delhi-110 007, India
,
a   Bioorganic Laboratory, Department of Chemistry, University of Delhi, Delhi-110 007, India
b   Department of Chemistry, Ramjas College, University of Delhi, Delhi-110 007, India
,
Priti Kumari
a   Bioorganic Laboratory, Department of Chemistry, University of Delhi, Delhi-110 007, India
,
Sunil K. Singh
c   Department of Chemistry, Kirori Mal College, University of Delhi, Delhi-110 007, India
,
Brajendra K. Singh
a   Bioorganic Laboratory, Department of Chemistry, University of Delhi, Delhi-110 007, India
› Author Affiliations
We are grateful for the financial support provided to advance research and development by the Institute of Eminence at the University of Delhi. Sumit Kumar [File No. 09/045(1798)/2020-EMR-I] and Aditi Arora [File No. 09/0045(11270)/2021-EMR-I] thank the Council of Scientific and Industrial Research, New Delhi, for the award of Senior Research Fellowship (SRF) and Junior Research Fellowship (JRF), respectively.


We dedicate this article to the fond memory of Late Prof. Ashok K. Prasad.

Abstract

A facile and efficient protocol for the diastereoselective synthesis of pyrano[3,2-c]quinolone carbohydrate derivatives from Perlin aldehydes and 4-hydroxyquinolones has been developed using a one-pot condensation at room temperature. In this investigation, glucose and galactose were employed as inexpensive starting materials to synthesize two sets of pyrano[3,2-c]quinolone-based carbohydrate conjugates. A total of sixteen novel compounds were successfully synthesized using this methodology in good to excellent yields. The reaction exhibited remarkable diastereoselectivity, resulting in a single diastereomeric product with a diastereomeric excess (dr) 97:3 for glucose, while a diastereomeric mixture with a diastereomeric excess (dr) 67:33 was obtained for galactose. The structural characterization of all sixteen compounds was carried out using various analytical techniques, including IR, 1H NMR, 13C NMR, 1H-1H COSY, 1H-13C HETCOR experiments, 2D NOESY NMR, and HRMS data. Additionally, the scalability of the protocol was successfully demonstrated by synthesizing one of the compounds on a gram scale, highlighting its potential for large-scale production.

Supporting Information



Publication History

Received: 31 July 2023

Accepted after revision: 07 September 2023

Article published online:
17 October 2023

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