Total synthesis of natural (+)-FR900482. 3. Completion of the synthesis

Article abstract of DOI:10.1016/0040-4039(96)00595-3

The title synthesis was accomplished by featuring (i) coupling of the aromatic fragment 2 with the optically active aliphatic fragment 3 to install the requisite carbon unit (2+3 → 4); (ii) intramolecular aldol reaction of the highly functionalized dialdehyde 10 to produce the desired eight-membered ring system 11 (10 → 11); (iii) epimerization of the C-7 position of hydroxy ketone 14 to obtain the correct stereochemistry (14 → 15); (iv) internal hemiacetal formation of hydroxylamino ketone 23 in situ generated from ketone 22 to construct the requisite tetracyclic ring system 24 (23 → 24) as key steps.