Total Synthesis of Cochleamycin A

Abstract

[reaction: see text] Cochleamycin A (1) was synthesized in 2.4% overall yield via a 23-step linear sequence starting from 3-butene-1-ol. Key features of the synthesis include the synthesis of (Z)-1,3-diene 21 via a Stille coupling of 4 and 5 and a transannular Diels-Alder reaction of macrocycle 26 to provide the complete carbon skeleton of 1.

Synthesis, anti-inflammatory activity of picen-13-ylmethylene derivatives

“…23 In our study, mild reducing agents like di-isobutyl aluminium hydride [DIBAL (1M in Toluene)] was used to reduce picene-13-carboxylic acid ethyl ester 6 to picen-13-ylmethanol 9 24 in 90% yield. It was found that the oxidation of compound 9 with manganese dioxide 11 in dichloromethane was not completed even under reflux condition.…”

Total syntheses of the archazolids: an emerging class of novel anticancer drugs

“…The crude aldehyde was then directly transformed into the ( Z) -α,β-unsaturated ester 62 as a single stereoisomer by a Still–Gennari [72] olefination with phosphonate 61 in an excellent yield of 93% over 4 steps. After reduction of ester 62 to the corresponding aldehyde (by a method that was not specified by the authors) phosphorane 63 was used to generate the respective Z -vinyl iodide in 85% yield as an 8:1 ( Z , Z) :( Z , E) mixture [91] which was later switched to the stannane 56 by lithium–halogen exchange and further treatment with Bu 3 SnCl [92] in 90% yield.…”

Total syntheses of bioactive natural products from carbohydrates

“…Not surprisingly, the combination of architectural complexities and bioactivities has engendered considerable interest, resulting in impressive synthetic studies from the groups of Paquette and Tadano using Diels-Alder reactions [107][108][109][110]. After our first total synthesis of cochleamycin A [97], Tadano's group reported the total synthesis of macquarimicin A (100) [109,110], and Roush's group disclosed his total synthesis of cochleamycin A [111]. Both groups took transannular Diels-Alder reactions to construct cochleamycin skeleton, as the formation of a 10-membered ring had been well known to be difficult.…”