The Total Synthesis of the Oxopolyene Macrolide RK‐397

Abstract

It works both ways: The convergent total synthesis of the oxopolyene macrolide RK‐397 utilizes remote asymmetric induction and a two‐directional chain synthesis to prepare the polyol portion of the molecule, as well as a cross‐metathesis reaction of a trienal with a terminal alkene to append the polyene to the polyol.

Rhodium-Catalyzed Endo-Selective Epoxide-Opening Cascades: Formal Synthesis of (−)-Brevisin

“…Ozonolysis of known enoate 9 , 21 followed by nucleophilic addition of isopropenyl magnesium bromide and a tandem vinylation–Claisen process 22 afforded aldehyde 10 . Olefination of 10 23 and subsequent asymmetric Shi epoxidation 24 and TBAF desilylation rapidly provides cascade precursor 5 in six steps from enoate 9 . 25 …”

Concise Synthesis of Acetal‐Protected syn 1,3‐Diols by a Tandem Hemiacetal Formation/Tsuji–Trost Reaction

“…Notably, this route compares favorably to all previous synthetic approaches to this unit. [16,17] Stereochemically, this domino process places all three substituents of the six-membered-ring products in equatorial positions, which may be explicable if these reactions proceed via a Zimmerman-Traxler-type transition state. The high degree of selectivity observed in this process can only be rationalized mechanistically if the initial hemiacetal formation is reversible and not stereodiscriminating.…”

De novo synthesis of natural products via the asymmetric hydration of polyenes

“…The first total synthesis of RK-397 was reported by McDonald in 2004, 56 which was subsequently followed by two more total syntheses in 2005 57 and 2007. 58 In addition, several approaches to the polyol portion of the natural product have been reported. 59 …”