A Direct and Efficientα-Selective Glycosylation Protocol for the Kedarcidin Sugar,L-Mycarose: AgPF6 as a Remarkable Activator of 2-Deoxythioglycosides

The α-selective effect and potency of AgPF6 on readily prepared 2-deoxythioglycosides allows the direct attachment of a partially protected allo-sugar, such as L-mycarose, to an advanced and hindered aglycon unit of kedarcidin (see picture). This method also permits access to other 2-deoxyglycosides in an expedient and mild manner. PMBM=p-methoxybenzyloxymethyl, Alloc=allyloxycarbonyl, TES=triethylsilyl.