179945-11-0Relevant articles and documents
An improved synthesis of (-)-brevisamide, a marine monocyclic ether amide of dinoflagellate origin
Tsutsumi, Ryosuke,Kuranaga, Takefumi,Wright, Jeffrey L.C.,Baden, Daniel G.,Ito, Emiko,Satake, Masayuki,Tachibana, Kazuo
experimental part, p. 6775 - 6782 (2010/10/02)
An improved synthesis of (-)-brevisamide a marine cyclic ether isolated from the red-tide dinoflagellate Karenia brevis was achieved. The ether ring portion was constructed from an unsaturated lactone, which was prepared enantioselectively via an Evans aldol reaction and one-pot lactonization in the presence of excessive base after an Ando reaction. The ether ring and a dienol side chain fragment were connected via Suzuki-Miyaura coupling.
A general synthetic approach for the synthesis of β-hydroxy-δ-lactones: asymmetric total synthesis of prelactones and epi-prelactones V and E
Sabitha, Gowravaram,Padmaja,Reddy, K. Bhaskar,Yadav
, p. 919 - 922 (2008/09/17)
A general synthetic approach for the synthesis of prelactones and epi-prelactones V and E has been reported using an Evans' aldol reaction as the key step.
The reaction mechanism of spirocylization and stereoselectivity studies for the calyculin C16-C25 fragment
Rauhala, Vesa,Naettinen, Kalle,Rissanen, Kari,Koskinen, Ari M. P.
, p. 4119 - 4126 (2007/10/03)
The mechanism of the double intramolecular hetero-Michael addition, a key reaction in the planned synthesis of the natural product calyculin C, has been studied by NMR. The cyclization follows Baldwin's rules and proceeds first through a six-membered ring
Aplyronine A, a potent antitumor substance of marine origin, aplyronines B and C, and artificial analogues: Total synthesis and structure-cytotoxicity relationships
Kigoshi, Hideo,Suenaga, Kiyotake,Mutou, Tsuyoshi,Ishigaki, Takeshi,Atsumi, Toshiyuki,Ishiwata, Hiroyuki,Sakakura, Akira,Ogawa, Takeshi,Ojika, Makoto,Yamada, Kiyoyuki
, p. 5326 - 5351 (2007/10/03)
The enantioselective total synthesis of aplyronine A (1), a potent antitumor substance of marine origin, was achieved by a convergent approach. Three segments 4, 5, and 6, corresponding to the C5-C11, C21-C27, and C28-C34 portions of aplyronine A (1), were prepared using the Evans aldol reaction and the Sharpless epoxidation as key steps. The coupling reaction of 4 with iodide 7 followed by Julia olefination with sulfone 8 gave the C5-C20 segment 9, while the Julia coupling reaction between segments 5 and 6 provided the C21-C34 segment 10. Julia olefination between segments 9 and 10 and the subsequent four-carbon homologation reaction led to seco acid 83, which was converted into aplyronine A (1) by Yamaguchi lactonization followed by the introduction of two amino acids. The use of the [(3,4-dimethoxybenzyl)oxy]methyl group as a protecting group for the hydroxyl at C29 was crucial for this synthesis. The enantioselective synthesis of two natural congeners, aplyronines B (2) and C (3), was also carried out using the intermediates for the synthesis of 1, which determined the absolute stereostructures of 2 and 3 unambiguously. To study the structure-cytotoxicity relationships of aplyronines, artificial analogues of 1 were synthesized and their cytotoxicities were evaluated: the trimethylserine moiety, two hydroxyl groups, and the side chain portion in 1 turned out to be important in the potent cytotoxicity shown by 1. Biological studies with aplyronine A (1) showed that 1 inhibited polymerization of G-actin to F-actin and depolymerized F-actin to G-actin.
Synthetic studies on aplyronine A, a potent antitumor substance of marine origin: Stereocontrolled synthesis of the C21-C34 segment
Kigoshi, Hideo,Ojika, Makoto,Suenaga, Kiyotake,Mutou, Tsuyoshi,Hirano, Junko,Sakakura, Akira,Ogawa, Takeshi,Nisiwaki, Masanori,Yamada, Kiyoyuki
, p. 1247 - 1250 (2007/10/02)
The C21-C34 segment 2 of aplyronine A (1), a potent antitumor substance of marine origin, was synthesized enantioselectivity in 25 steps (17% overall yield) from imide 11.
