Acetal Substitution and Cleavage Reactions

Protected propargyl C-glycosides can be prepared by the activation of the anomeric carbon center of a benzyl protected glucose derivative with BF3 OEt2 to favor the a-anomer product (152) (Equation 91) [93]. 

Ravina and coworkers have disclosed the use of boron (III) bromide to cleanly deprotect 2-MOM -pyridazinone (153) without affecting the double bond and furnish the deprotected pyridazinone (154) in almost quantitative yield (Equation 92) [94]. 

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