Synthesis of Septanosides via Hemiacetal Formation

SCHEME 13.2 Formation of (a) septanoside from an isopropylidene protected pyranoside 4 [11] and (b) septanose from trityl-functionalized aldohexose 6 [12], 

An interesting observation of septanoside formation was reported by Murphy and coworkers, when studying epoxidations of 6-deoxy hex-5-enopyranosides [15]. Thus, epoxidation of 13 for a prolonged period in the presence of oxone and 1,1,1,-trifluoroacetone, followed by hydrolysis, afforded hexos-5-ulose 14, which, upon 

SCHEME 133 Cyclization of linear precursors to (a) septanose 9 [13] and (b) septanoside 12 [14]. 

SCHEME 13.4 Reactions of 6-deoxy-5-enopyranoside to prepare septanoside 16 [15], 

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