Mannopyranosyl uronic acid donor reactivity
Marthe T C Walvoort1, Wilbert de Witte, Jesse van Dijk
1Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
Abstract:
The reactivity of a variety of mannopyranosyl uronic acid donors was assessed in a set of competition experiments, in which two (S)-tolyl mannosyl donors were made to compete for a limited amount of promoter (NIS/TfOH). These experiments revealed that the reactivity of mannuronic acid donors is significantly higher than expected based on the electron-withdrawing capacity of the C-5 carboxylic acid ester function. A 4-O-acetyl-β-(S)-tolyl mannuronic acid donor was found to have similar reactivity as per-O-benzyl-α-(S)-tolyl mannose.
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