A CONCISE ROUTE TO A KEY INTERMEDIATE IN THE TOTAL SYNTHESES OF (+)-TIRANDAMYCIC ACID AND (-)-TIRANDAMYCIN A

Article abstract of DOI:10.1016/S0040-4020(01)85948-2

An efficacious, asymmetric synthesis of the 2,9-dioxabicyclo<3.3.1>nonane 4 has been completed in nine chemical steps from 4,5-dimethylfuraldehyde (8).Since enantiomerically pure 4 has been previously converted in five steps by Ireland into (+)-tirandamycic acid (3) and more recently by Schlessinger into(-)-tirandamycin A(1), this achievement constitutes in a strictly formal sense the total syntheses of these substances.The key step in the synthesis of 4 features the transformation of the enantiomerically pure furfuryl diol 25 into 29 by initial selective oxidation of the furan ring and subsequent acid-catalyzed bicycloketalization.