184091-30-3Relevant academic research and scientific papers
Forskolin studies
Behnke, Dirk,Hennig, Lothar,Findeisen, Matthias,Welzel, Peter,Müller, Dietrich,Thormann, Michael,Hofmann, Hans-J?rg
, p. 1081 - 1095 (2000)
A new nucleophilic isoprenoid C5 reagent is introduced which allowed synthesis of an advanced and optically active forskolin intermediate in a very efficient way. In addition, docking experiments that are based on X-ray results indicate that there might exist forskolin analogues with improved properties as far as binding to adenylyl cyclases and synthetic accessibility are concerned. (C) 2000 Elsevier Science Ltd.
Spongipyran synthetic studies. Evolution of a scalable total synthesis of (+)-spongistatin 1
Smith III, Amos B.,Sfouggatakis, Chris,Risatti, Christina A.,Sperry, Jeffrey B.,Zhu, Wenyu,Doughty, Victoria A.,Tomioka, Takashi,Gotchev, Dimitar B.,Bennett, Clay S.,Sakamoto, Satoshi,Atasoylu, Onur,Shirakami, Shohei,Bauer, David,Takeuchi, Makoto,Koyanagi, Jyunichi,Sakamoto, Yasuharu
scheme or table, p. 6489 - 6509 (2011/02/25)
Three syntheses of the architecturally complex, cytotoxic marine macrolide (+)-spongistatin 1 (1) are reported. Highlights of the first-generation synthesis include: use of a dithiane multicomponent linchpin coupling tactic for construction of the AB and CD spiroketals, and their union via a highly selective Evans boron-mediated aldol reaction en route to an ABCD aldehyde; introduction of the C(44)-C(51) side chain via a Lewis acid-mediated ring opening of a glucal epoxide with an allylstannane to assemble the EF subunit; and final fragment union via Wittig coupling of the ABCD and EF subunits to form the C(28)-C(29) olefin, followed by regioselective Yamaguchi macrolactonization and global deprotection. The second- and third-generation syntheses, designed with the goal of accessing 1 g of (+)-spongistatin 1 (1), maintain both the first-generation strategy for the ABCD aldehyde and final fragment union, while incorporating two more efficient approaches for construction of the EF Wittig salt. The latter combine the original chelation-controlled dithiane union of the E- and F-ring progenitors with application of a highly efficient cyanohydrin alkylation to append the F-ring side chain, in conjunction with two independent tactics to access the F-ring pyran. The first F-ring synthesis showcases a Petasis-Ferrier union/rearrangement protocol to access tetrahydropyrans, permitting the preparation of 750 mg of the EF Wittig salt, which in turn was converted to 80 mg of (+)-spongistatin 1, while the second F-ring strategy, incorporates an organocatalytic aldol reaction as the key construct, permitting completion of 1.009 g of totally synthetic (+)-spongistatin 1 (1). A brief analysis of the three syntheses alongside our earlier synthesis of (+)-spongistatin 2 is also presented.
Spongistatin synthetic studies. An efficient, second-generation construction of an advanced ABCD intermediate
Smith III, Amos B.,Doughty, Victoria A.,Sfouggatakis, Chris,Bennett, Clay S.,Koyanagi, Jyunichi,Takeuchi, Makoto
, p. 783 - 786 (2007/10/03)
(formula presented) A short, efficient, and stereocontrolled synthesis of (-)-4, an advanced ABCD subunit of the spongistatins, has been achieved. Central to the synthetic strategy is the multicomponent linchpin union of silyl dithianes with epoxides to access both the AB and CD fragments. Fragment coupling was then achieved via an efficient stereoselective aldol reaction. The linear sequence required 22 steps and proceeded in 4.0% overall yield.
Regioselective nucleophilic ring opening reactions of 2,2-disubstituted aziridines - The asymmetric synthesis of α,α-disubstituted amino acids
Burgaud, Beatrice G. M.,Horwell, David C.,Padova, Allessandro,Pritchard, Martyn C.
, p. 13035 - 13050 (2007/10/03)
In this paper a broadly applicable synthesis of chiral α,α-disubstituted amino acids is outlined based upon regioselective ring opening of aziridine derivatives. Examples of nitrogen, sulphur and carbon nucleophiles were found to preferentially attack the C3 position of chiral 2-methyl-2-silyloxymethyl aziridines to provide a range of α,α-disubstituted amino acid derivatives in good yield.
