Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

A range of biologically significant imino and amino sugars [1,4-dideoxy-1,4-imino-D-allitol, 3,6-dideoxy-3,6-imino-L-allonic acid, (3R,4S)-3,4-dihydroxy-L-proline, 1,5-anhydro-4-deoxy-4-amino-D-glucitol, and 1,5-anhydro-4-deoxy-4-amino-L-iditol] has been prepared via stereospecific cyclization of α,ε-dihydroxy-β-amino esters. These substrates are readily prepared via conjugate addition of lithium (S)-N-benzyl-N-(α-methylbenzyl)amide to enantiopure α,β-unsaturated esters (β-substituted with cis- and trans-dioxolane units) coupled with in situ enolate oxidation with camphorsulfonyloxaziridine (CSO). Activation of the ε-hydroxyl group allowed cyclization to either the corresponding pyrrolidine or the tetrahydropyran scaffold, with the course of the cyclization process being dictated by the relative configuration of the dioxolane unit. When the α,ε-dihydroxy-β-amino ester bears a cis-dioxolane unit, cyclization occurs upon attack of the β-amino substituent to give the corresponding pyrrolidine after in situ N-debenzylation. In contrast, when the α,ε-dihydroxy-β-amino ester bears a trans-dioxolane unit, cyclization occurs upon attack of the α-hydroxyl substituent to give the corresponding tetrahydropyran.

Original publication

DOI

10.1021/jo5018298

Type

Journal article

Journal

J Org Chem

Publication Date

17/10/2014

Volume

79

Pages

9686 - 9698

Keywords

Amino Sugars, Crystallography, X-Ray, Cyclization, Esters, Imines, Lithium, Molecular Structure, Oxidation-Reduction, Proline, Pyrans, Stereoisomerism