556104-38-2Relevant 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.
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.
Total synthesis of ustiloxin D and considerations on the origin of selectivity of the asymmetric allylic alkylation
Sawayama, Andrew M.,Tanaka, Hiroko,Wandless, Thomas J.
, p. 8810 - 8820 (2007/10/03)
As part of investigations into cell cycle checkpoint inhibitors, an asymmetric synthesis of the antimitotic natural product, ustiloxin D, has been completed. A salen-Al-catalyzed aldol reaction was employed to construct a chiral oxazoline 9 (99% yield, 98
Enantioselective total synthesis of ustiloxin D
Tanaka, Hiroko,Sawayama, Andrew M.,Wandless, Thomas J.
, p. 6864 - 6865 (2007/10/03)
Ustiloxin D and phomopsin A are potent antimitotic agents that bind to tubulin and interfere with cellular microtubule function. A synthetic strategy has been developed to allow access to both of the natural products as well as a variety of variants of th
