Ring Opening of Oxyglycal Derived 1,2-Cyclopropane

SCHEME 13.19 Ring-opening of oxyglycai derived em-dibromocyclopropane 64 to sep-tanoside 66 [31a]. 

SCHEME 13.20 Ring-opening of oxyglycal derived gem-dichlorocyclopropane 67 to phenyl (68), azido- (69) septanosides, and septanoside-containing disaccharides 70 and 71 [31b]. 

Appropriately protected furanoside and pyranoside were chosen as nucleophiles in the ring opening of 67 to generate septanoside-containing disaccharides 70 and 71, respectively [31b]. 

SCHEME 13.23 Acid-catalyzed ring-opening of glycal-derived ge/n-dichlorocyclopropane derivative 67 to chloro-oxepines 84 and 85 [32]. 

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