960595-76-0Relevant academic research and scientific papers
Evolution of the total syntheses of ustiloxin natural products and their analogues
Li, Pixu,Evans, Cory D.,Wu, Yongzhong,Cao, Bin,Hamel, Ernest,Joullie, Madeleine M.
, p. 2351 - 2364 (2008/09/20)
Ustiloxins A-F are antimitotic heterodetic cyclopeptides containing a 13-membered cyclic core structure with a synthetically challenging chiral tertiary alkyl-aryl ether linkage. The first total synthesis of ustiloxin D was achieved in 31 linear steps using an SNAr reaction. An NOE study of this synthetic product showed that ustiloxin D existed as a single atropisomer. Subsequently, highly concise and convergent syntheses of ustiloxins D and F were developed by utilizing a newly discovered ethynyl aziridine ring-opening reaction in a longest linear sequence of 15 steps. The approach was further optimized to achieve a better macrolactamization strategy. Ustiloxins D, F, and eight analogues (14-MeO-ustiloxin D, four analogues with different amino acid residues at the C-6 position, and three (9R,10S)-epi-ustiloxin analogues) were prepared via the second-generation route. Evaluation of these compounds as inhibitors of tubulin polymerization demonstrated that variation at the C-6 position is tolerated to a certain extent. In contrast, the S configuration of the C-9 methylamino group and a free phenolic hydroxyl group are essential for inhibition of tubulin polymerization.
The enantioselective synthesis of phomopsin B
Grimley, Joshua S.,Sawayama, Andrew M.,Tanaka, Hiroko,Stohlmeyer, Michelle M.,Woiwode, Thomas F.,Wandless, Thomas J.
, p. 8157 - 8159 (2008/09/18)
Proven approach to a family of antimitotics: The total synthesis of phomopsin B, an antimitotic natural product, was achieved by assembling two fragments of equal complexity in a longest linear sequence of 26 steps. The approach features two catalytic tra
A regio- and stereoselective approach to quaternary centers from chiral trisubstituted aziridines
Forbeck, Erin M.,Evans, Cory D.,Gilleran, John A.,Li, Pixu,Joullie, Madeleine M.
, p. 14463 - 14469 (2008/09/17)
A thorough investigation of a regio- and stereospecific aziridine ring opening reaction presents new synthetic technology for the construction of a variety of quaternary β-substituted-α-amino functional groups. Mild, metal-free reaction conditions allow f
A convergent total synthesis of ustiloxin D via an unprecedented copper-catalyzed ethynyl aziridine ring-opening by phenol derivatives
Li, Pixu,Evans, Cory D.,Joullie, Madeleine M.
, p. 5325 - 5327 (2007/10/03)
(Chemical Equation Presented) The ustiloxins are a family of heterodetic cyclopeptides that have been isolated from the water extracts of false smut balls on the panicles of rice plants caused by the fungus Ustilaginoidea virens. A concise total synthesis of ustiloxin D has been achieved via an unprecedented ethynyl aziridine ring-opening of phenol derivatives. The longest linear sequence of the synthesis is 15 steps from commercially available compounds.
