Organocatalytic Stetter Cyclization of Pentoses for the Synthesis of Polyhydroxylated Cyclopentanone Scaffolds

TL;DR

This paper presents a new method to create complex cyclopentanone structures from pentose sugars using organocatalysis.

Contribution

A novel organocatalytic Stetter cyclization method for synthesizing polyhydroxylated cyclopentanone scaffolds from aldopentoses.

Findings

The method introduces an intramolecular Michael acceptor for efficient Stetter cyclization.

Multiple chiral centers and protected hydroxy groups are formed in the resulting cyclopentanone scaffolds.

Stereochemical permutations can be easily prepared using commercially available d- and l-pentoses.

Abstract

An organocatalytic
approach for the carbocyclization
of aldopentoses
is disclosed. After initial activation, with the introduction of the
intramolecular Michael acceptor in the substrate, the NHC-catalyzed
Stetter reaction can be performed, giving rise to cyclopentanone scaffolds
bearing multiple chiral centers and protected hydroxy groups. An optional
controlled one-pot elimination provides the corresponding cyclopentenones
as well. Due to the commercial availability of d- and l-pentoses all possible stereochemical permutations of the products
can be prepared conveniently and affordably.

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