Glycosidation Methods in Carbohydrate Synthesis

In contrast to this sequence of events, when the C-2 position is occupied by an ester, a phenylthio, or a phenylseleno group, a preliminary intramolecular cyclization occurs prior to the addition of 

In rounding out this foray into glycosidation chemistry, it would be most appropriate to close with the glycal method, a procedure that has found numerous applications in total synthesis endeavors. In this general strategy, pioneered by Lemieux and co-workers 

While this concludes our condensed survey of glycosidation techniques, we hope that your comprehension of the remainder of this chapter, where most of the approaches defined above will be revisited, will now be sufficiently facilitated. Thus, without further delay, we turn to the main theme of this chapter s story, the total synthesis of eveminomicin 13,384-1 (1).  

Aside from these potentially thorny problems, from a retrosyn-thetic standpoint everninomicin 13,384-1 (1) is perhaps an ideal candidate for a convergent synthesis, as the modular nature of the target leads to the appealing prospect of synthesizing each compo- 

C-3 linked congener in the hope that one of these precursors would provide 64 with the stereochemical arrangements of everninomicin. 

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