Total Synthesis of Bryostatin 2 Evans

The synthesis of the BC-ring fragment 26 begins with the enantioselective aldol reaction of aldehyde 22 and chiral boron enolate 23 derived from (—)-DIP-Cl as described by Paterson and Brown [42]. The aldol adduct 24 is converted to the 

3 Steps including hydroxy directed reduction of C3 ketone 

4 Steps including hydroxy directed diastereoselective Tischenko reaction 

11 Steps including hydroxy directed alkyne hydroalumination-iodination 

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