β-l-Rhamnosylation and β-d-Mannosylation Mediated by 4--Ester Groups in a Weakly Nucleophilic Environment.

Org Lett

National Glycoengineering Research Center and Shandong Key laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, 72 Binhai Rd Qingdao 266237, China.

Published: October 2023

-4--Acyl group directed β-rhamnosylation and β-mannosylation are achieved in a carborane or BARF anion formed weakly nucleophilic environment with the assistance of a 2,3-orthocarbonate group. The 4--acyl group plays a critical role in directing the β-selectivity, and the weakly coordinating anion is essential to amplify this direction. The orthocarbonate group could be readily removed with 1,3-propanediol in the presence of BF·EtO.

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http://dx.doi.org/10.1021/acs.orglett.3c02566DOI Listing

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