A FORMAL SYNTHESIS OF APLASMOMYCIN - ASSEMBLY OF THE C3-C17 SEGMENT BASED ON 1,3-ASYMMETRIC AND 1,5-ASYMMETRIC REDUCTIONS

The C3-C17 segment of a boron containing ionophoric antibiotic aplasmomycin (1), the key intermediate in Corey's total synthesis of 1, was stereoselectively synthesized in an optically active form. This synthesis involved stereoselective construction of the two segments, (+)-dithiane 3 (C3-C11) and (+)-aldehyde 4 (C12-C17), based on remote controlled asymmetric reductions of the corresponding ketones as key steps and connection of 3 and 4 through the trans-double bond to elaborate the (+)-dithiane 2 (C3-C17), the key intermediate in Corey's total synthesis of 1. © 1990.