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DOI: 10.1055/s-0033-1340712
Total Synthesis of (–)-Angiolam A
Publication History
Publication Date:
17 February 2014 (online)
Significance
Isolated in 1985 from Angiococcus disciformis, angiolam A displays antibacterial activity against Gram-positive bacteria. Gieseler and Kalesse report the first total synthesis of this lactone–lactam macrocyclic antibiotic in 18 linear steps and establish that its absolute configuration is opposite to the originally proposed structure.
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Comment
Formation of the four chiral centers of fragment J involves two sequences of stereoselective vinylogous Mukaiyama aldol reaction and subsequent conjugate reduction–diastereoselective protonation. Epimerization at C4 (1:1) occurred during olefination with fragment K, but fortunately, isomerically pure angiolam A could be isolated after full deprotection of macrocycle L.
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