Replacement of the bryostatin A- and B-pyran rings with phenyl rings leads to loss of high affinity binding with PKC

We describe a convergent synthesis of a bryostatin analogue in which the natural A- and B-ring pyrans have been replaced by phenyl rings. The new analogue exhibited PMA like behavior in cell assays, but failed to maintain high affinity binding for PKC, despite retaining an unaltered C-ring ‘binding domain’