G. Bringmann et al., Octadehydromichellamine, a structural analog of the anti-HIV michellamineswithout centrochirality, TETRAHEDRON, 55(6), 1999, pp. 1731-1740
The synthesis of octadehydromichellamine (4), as the fully dehydrogenated s
tructural analog of the naturally occurring michellamines (1), is described
. This derivative is the first michellamine-type quateraryl without centroc
hirality and thus constitutes a distinctly simplified structural michellami
ne analog. Key step of the total synthesis is the twofold coupling of a bis
-O-triflate activated central binaphthalene building block 9 with 2 eq. of
the isoquinoline boronic acid 8, to give the quateraryl 11, whose deprotect
ion delivers the target molecule 4, in an apparently stereochemically pure
form. Octadehydromichellamine (4) shows a good order of anti-HIV activity a
nd, compared with natural michellamines, enhanced antimalarial activity aga
inst Plasmodium falciparum. (C) 1999 Elsevier Science Ltd. All rights reser
ved.