Direct aldol strategy in enantioselective total synthesis of thuggacin b

An enantioselective total synthesis of thuggacin B, a natural product exhibiting antibiotic activity against Mycobacterium tuberculosis, is described. Asymmetric direct aldol reactions promoted by Cu and Zn catalysts play a pivotal role in constructing four stereogenic centers. The use of direct aldol reactions as the initial steps for the synthesis of two key fragments allowed the construction of the other stereogenic centers through chirality transfer. Antibiotic activity against Mycobacterium tuberculosis is exhibited by the natural product thuggacin B, the enantioselective total synthesis of which is described. Catalytic asymmetric direct aldol reactions promoted by Cu and Zn catalysts played a pivotal role in constructing four stereogenic centers. The execution of direct aldol reactions as the initial steps for the synthesis of two key fragments allowed the construction of the other stereogenic centers through chirality transfer. PG=protecting group.