- Remote stereocontrol in reactions between 4- and 5-alkoxyalk-2- enylstannanes and 1-alkoxycarbonylimines and analogues: Stereoselective approaches to novel α-amino acids
-
Reactions of the allyltin trichloride 45 generated from (4S)-4-benzyloxypent-2-enyl(tributyl)stannane 1 with imines prepared from glyoxylates proceed with useful levels of 1,5-stereocontrol in favour of (4E)-2,6-anti-2-(alkylamino)-6-benzyloxyhept-4-enoat
- Hallett, David J.,Tanikkul, Nongluk,Thomas, Eric J.
-
experimental part
p. 6130 - 6158
(2012/09/05)
-
- Total synthesis of the large non-ribosomal peptide polytheonamide B
-
Polytheonamide B is by far the largest non-ribosomal peptide known at present, and displays extraordinary cytotoxicity (EC50 =68 pg ml -1 , mouse leukaemia P388 cells). Its 48 amino-acid residues include a variety of non-proteinogenic d- and l-amino acids, and the absolute stereochemistry of these amino acids alternate in sequence. These structural features induce the formation of a stable β-strand-type structure, giving rise to an overall tubular structure over 30A? in length. In a biological setting, this fold is believed to transport cations across the lipid bilayer through a pore, thereby acting as an ion channel. Here, we report the first chemical construction of polytheonamide B. Our synthesis relies on the combination of four key stages: syntheses of non-proteinogenic amino acids, a solid-phase assembly of four fragments of polytheonamide B, silver-mediated connection of the fragments and, finally, global deprotection. The synthetic material now available will allow studies of the relationships between its conformational properties, channel functions and cytotoxicity.
- Inoue, Masayuki,Shinohara, Naoki,Tanabe, Shintaro,Takahashi, Tomoaki,Okura, Ken,Itoh, Hiroaki,Mizoguchi, Yuki,Iida, Maiko,Lee, Nayoung,Matsuoka, Shigeru
-
supporting information; scheme or table
p. 280 - 285
(2010/09/03)
-
- One-pot synthesis of α-amino acids based on free radical-mediated carbon-carbon bond formation
-
The one-pot reaction of 2-hydroxy-2-methoxyacetic acid methyl ester with benzyloxyamine and an alkyl radical provided a convenient method for preparing the protected α-amino acids via a carbon-carbon bond formation by intermolecular carbon radical additio
- Miyabe, Hideto,Yoshioka, Naoko,Ueda, Masafumi,Naito, Takeaki
-
p. 3659 - 3660
(2007/10/03)
-