Very high chemoselective, regioselective, and E-stereoselective 1,3-chirality transfer involving reaction of acyclic (E)- and (Z)-.gamma.-mesyloxy .alpha.,.beta.-enoates and organocyanocopper-trifluoroborane reagents. Efficient synthetic routes to functionalized chiral .alpha.-alkyl (E)-.beta.,.gamma.-enoates and (E)-allylic alcohols with high optical purity
Very high chemoselective, regioselective, and E-stereoselective 1,3-chirality transfer involving reaction of acyclic (E)- and (Z)-.gamma.-mesyloxy .alpha.,.beta.-enoates and organocyanocopper-trifluoroborane reagents. Efficient synthetic routes to functionalized chiral .alpha.-alkyl (E)-.beta.,.gamma.-enoates and (E)-allylic alcohols with high optical purity
The challenging synthesis of a quaternary center within the highly oxygenated setting of tedanolide C can be performed via a Kiyooka aldol reaction. Here, the diastereomeric analog of tedanolide C with the configurations between C10 and C20 opposite compared to the proposed structure was chosen as the synthetic target. The tetra-substituted silyl ketene acetal provides the southern hemisphere of tedanolide C in useful selectivities, and the absolute configuration of the newly generated quaternary center was determined by NOE experiments of the corresponding acetonide.