摘要:
A convergent, stereoselective assembly of the C1-C21 (Cl'-C21') fragment of SCH 351448, a 28-membered bis-lactose natural product, has been developed. A highly efficient approach to this fragment assembles 75% of the carbon skeleton and all the stereochemical elements present in the natural product. In addition, an interesting boron ligand effect on the diastereoselectivity of a key aldol reaction with methyl ketone-derived enolborinates is reported.