90865-69-3Relevant academic research and scientific papers
Synthesis of optically active β- Or γ-alkyl-substituted alcohols through copper-catalyzed asymmetric allylic alkylation with organolithium reagents
Guduguntla, Sureshbabu,Fananas-Mastral, Martin,Feringa, Ben L.
, p. 8274 - 8280 (2013/09/24)
An efficient one-pot synthesis of optically active β-alkyl-substituted alcohols through a tandem copper-catalyzed asymmetric allylic alkylation (AAA) with organolithium reagents and reductive ozonolysis is presented. Furthermore, hydroboration-oxidation following the Cu-catalyzed AAA leads to the corresponding homochiral γ-alkyl-substituted alcohols.
Process for total synthesis of pladienolide B and pladienolide D
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Page/Page column 34, (2010/11/29)
[Problems to be Solved] To provide an effective process for total synthesis of pladienolide B and pladienolide D having excellent anti-tumor activity and to provide useful intermediates in the above-described process. [Measure for Solving the Problem] A process for producing a compound represented by Formula (11): wherein P1, P7, P8, P9 and R1 are the same as defined below, characterized by including reacting a compound represented by Formula (12): wherein P7 means a hydrogen atom or a protecting group for hydroxy group; R1 means a hydrogen atom or a hydroxy group, with a compound represented by Formula (13): wherein P1 means a hydrogen atom or a protecting group for hydroxy group; P8 means a hydrogen atom, an acetyl group or a protecting group for hydroxy group; P9 means a hydrogen atom or a protecting group for hydroxy group; or P8 and P9 may form together a group represented by a formula: wherein R5 means a phenyl group which may have a substituent, in the presence of a catalyst.
Total synthesis of the potent antitumor macrolides pladienolide B and D
Kanada, Regina M.,Itoh, Daisuke,Nagai, Mitsuo,Niijima, Jun,Asai, Naoki,Mizui, Yoshiharu,Abe, Shinya,Kotake, Yoshihiko
, p. 4350 - 4355 (2008/03/12)
Getting cross: The total syntheses of two pladienolides (see picture), which have prominent antitumor activity based on a unique mechanism of action, have been accomplished, and their absolute configurations were verified. The 12-membered aliphatic macrolide structure was formed by ring-closing metathesis, and the side-chain moiety was coupled to the macrolide by Julia-Kocienski olefination or cross-metathesis. (Chemical Equation Presented).
Synthetic studies toward amphidinolide H1: Segment C14-C26
Deng, Lisheng,Ma, Zhixiong,Zhang, Yazhu,Zhao, Gang
, p. 87 - 90 (2008/03/13)
Stereoselective synthesis of the C14-C26 moiety of amphidinolide H1 is described. The key features of the approach include the convergent fragment assembly with a highly diastereoselective aldol reaction to establish the C18 stereochemistry and using comm
Hydride reduction of alpha, beta-unsaturated carbonyl compounds using chiral organic catalysts
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Page/Page column 20-21, (2008/06/13)
Nonmetallic, chiral organic catalysts are used to catalyze the 1,4-hydride reduction of an α,β-unsaturated carbonyl compound. The α,β-unsaturated carbonyl compound may be an aldehyde or cyclic ketone, and the hydride donor may be a dihydropyridine. The reaction is enantioselective, and proceeds with a variety of hydride donors, catalysts, and substrates. The invention also provides compositions effective in carrying out the 1,4-hydride addition of α,β-unsaturated carbonyl compounds.
Asymmetric Total Synthesis of Dendrobatid Alkaloids: Preparation of Indolizidine 251F and Its 3-Desmethyl Analogue Using an Intramolecular Schmidt Reaction Strategy
Wrobleski, Aaron,Sahasrabudhe, Kiran,Aube, Jeffrey
, p. 5475 - 5481 (2007/10/03)
Total syntheses of alkaloid 251F (1), a natural product detected from the skin extracts of the dendrobatid frog species Minyobates bombetes, and its racemic 3-desmethyl derivative (2) are reported. A Diels-Alder reaction initiated both syntheses and established four consecutive stereogenic centers. Important to the synthesis of 2 was a first-generation ozonolysis/olefination/aldol strategy to convert a [2.2.1] bicyclic acid to the [3.3.0]bicyclooctane diquinane 4b. Further elaboration to an appropriate keto azide allowed for a key intramolecular Schmidt reaction to deliver the tricyclic core of the target molecule. In a second-generation approach, a tandem ring-opening/ring-closing metathesis reaction effected an overall [2.2.1] → [3.3.0] skeletal rearrangement to deliver diquinane 4a. In similar fashion, 4a was manipulated to an appropriate keto azide, and an intramolecular Schmidt reaction generated the core cyclic architecture of 251F.
Total synthesis of antitumor depsipeptide (-)-doliculide.
Ghosh,Liu
, p. 635 - 638 (2007/10/03)
[reaction: see text] (-)-Doliculide, a potent antitumor agent, is synthesized stereoselectively in a convergent manner. The key strategy involves a stereoselective synthesis of the polyketide unit and synthesis of the D-tyrosine derivative, followed by as
Synthesis of Optically Active Bifunctional Isoprenoid Building Blocks by Rhodium(I)-Catalyzed Asymmetric Allylamine to Enamine Isomerization
Schmid, Rudolf,Hansen, Hans-Juergen
, p. 1258 - 1275 (2007/10/02)
The application of the known asymmetric allylamine to enamine isomerization methodology to bifunctional C5-isoprenoid allylic amines of types IId and IIe (Scheme 1) is described.It is shown that a number of such substrates can be isomerized with enantioselectivities of >90percent ee using cationic RhI complexes containing (6,6'-dimethylbiphenyl-2,2'-diyl)bis(diphenylphosphine) (BIPHEMP; 9) as asymmetry-inducing ligand (Scheme 2, Tables 1 and 2).Synthetically most useful is the isomerization of the benzyloxy derivative 10a into the (E)-enamine 11a.This isomerization proceeds with very high enantioselectivity (98-99percent ee) and affords, after enamine hydrolysis, the optically active 4-(benzyloxy)-3-methylbutanals ((R)- or (S)-12) in chemical yields of ca. 90percent.In conjunction, a short synthetic route to the starting material 10a has been developed which has a Pd-catalyzed amination of isoprene epoxide (30) as the key step.Thus, convenient and practical access to the optically active aldehydes (R)- and (S)-12 is now at hand.These aldehydes are useful optically active bifunctional building blocks for isoprenoid homologation.
