143236-77-5Relevant academic research and scientific papers
Asymmetric total synthesis of (-)-rasfonin
Bhuniya, Rajib,Nanda, Samik
, p. 1153 - 1165 (2013/02/25)
An efficient chemoenzymatic asymmetric synthesis of pyranone containing natural product (-)-rasfonin is presented here. Enantioselective enzymatic desymmetrization (EED) and a unique Gluconobacter oxydans mediated oxidative kinetic resolution (OKR) have been successfully employed to install three stereocenters (C6′, C7, and C9) of the target molecule. Stereoselective Achmatowicz reaction of a properly decorated furyl nucleus led to the core pyranone structure of rasfonin. At the late stage of the synthesis Negishi coupling has been used to complete the synthesis.
Highly stereoselective total synthesis of (+)-9-epi-Dictyostatin and (-)-12,13-Bis-epi-dictyostatin
Zanato, Chiara,Pignataro, Luca,Ambrosi, Andrea,Hao, Zhongyan,Trigili, Chiara,Diaz, Jose Fernando,Barasoain, Isabel,Gennari, Cesare
, p. 2643 - 2661 (2011/06/25)
The total syntheses of (+)-9-epi-dictyostatin (1a) and (-)-12,13-bis-epi- dictyostatin (1b), diastereomers of the antimitotic marine sponge-derived macrolide (-)-dictyostatin (1), were achieved by creating 11 stereogenic centers and 4stereogenic double bonds with a high level of stereocontrol. The yield for the 29-step longest linear sequence from Roche ester was 1.53 and 1.52%, respectively. The final key steps to these unnatural products were the addition of vinylzincates C10-C26 to aldehyde C1-C9 (leading surprisingly to complete stereoselectivity for the 9R-configuration in 28a and for the 9S-configuration in 12,13-bis-epimeric 28b), followed by Yamaguchi macrolactonization and global deprotection. (-)-12,13-Bis-epi-dictyostatin (1b) displayed a dramatic decrease of cytotoxicity and of the affinity toward the paclitaxel binding site of microtubules. Eleven stereogenic centers and fourstereogenic double bonds were obtained with a high level of stereocontrol in the total synthesis of (+)-9-epi-dictyostatin and(-)-12,13-bis-epi-dictyostatin, diastereomers of the antimitotic marine sponge-derived macrolide (-)-dictyostatin.
Total synthesis of 10-deoxymethynolide and narbonolide
Xuan, Richeng,Oh, Hong-Se,Lee, Younghoon,Kang, Han-Young
, p. 1456 - 1461 (2008/09/16)
(Chemical Equation Presented) A flexible and convenient approach was developed for the synthesis of 10-deoxymethynolide (1) and narbonolide (2), which are aglycones of the methymycin and the pikromycin families of macrolide antibiotics. These lactones are
A highly stereoselective synthesis of the C10-C23 fragment of (-)-dictyostatin
Monti, Chiara,Sharon, Ofer,Gennari, Cesare
, p. 4271 - 4273 (2008/03/27)
A highly stereoselective synthesis of the C10-C23 fragment of (-)-dictyostatin has been achieved using a Carreira alkynylation and a Marshall-Tamaru allenylzinc addition as key steps. The Royal Society of Chemistry.
Formal total synthesis of the polyketide macrolactone narbonolide
Venkatraman, Lakshmanan,Aldrich, Courtney C.,Sherman, David H.,Fecik, Robert A.
, p. 7267 - 7272 (2007/10/03)
An improved synthesis of (3S)-3-dihydronarbonolide is reported that constitutes a formal total synthesis of the 14-membered macrolactone antibiotic narbonolide. The key step was an intramolecular Nozaki-Hiyama-Kishi coupling to accomplish macrocyclization
Total Synthesis of Ionomycin Using Ring-Opening Strategies
Lautens, Mark,Colucci, John T.,Hiebert, Sheldon,Smith, Nicholas D.,Bouchain, Giliane
, p. 1879 - 1882 (2007/10/03)
(Matrix Presented) The total synthesis of the polyether antibiotic ionomycin, a calcium ionophore, is described. The synthesis demonstrates the utility of ring-opening methodologies as applied to the synthesis of polypropionate and deoxypolypropionate subunits, which are found in two of the four fragments in the synthesis.
Synthesis of salinomycin
Kocienski, Philip J.,Brown, Richard C. D.,Pommier, Agnes,Procter, Martin,Schmidt, Bernd
, p. 9 - 40 (2007/10/03)
Salinomycin, a commercially significant coccidiostat isolated from Streptomyces albus, has been synthesised from three principal fragments.Key steps include (a) the use of η3-allylmolybdenum cationic complexes 21a,b for the stereoselective construction of two contiguous stereogenic centres in fragment 5a; (b) the electrophilic cyclisation of 2-(prop-2-ynyl)-2-hydroxyoxanes to give molybdenum and chromium carbene complexes which are precursors to the furan fragment 7; (c) the diastereoselective oxidation of a 1,5-diene with potassium permanganate to generate four stereogenic centres in a single step leading to fragment 8; (d) the oxidative rearrangement of acylfuran 89 en route to the 1,6,8-trioxadispiropentadec-13-ene dispiroacetal core; and finally (e) the use of an allenol ether as an acyl anion equivalent together with the stereoselective hydrolysis of allenol ether intermediate 112 in an alternative synthesis of the dispiroacetal core.
Synthetic Investigations of Rapamycin. 1. Synthesis of a C10-C21 Fragment
Meyer, Stephanie D.,Miwa, Tetsuo,Nakatsuka, Masashi,Schreiber, Stuart L.
, p. 5058 - 5060 (2007/10/02)
Phosphine oxide 2, representing the C10-C21 portion of rapamycin, was stereoselectively synthesized and was demonstrated to undergo a Horner-Wittig reaction to form triene 25 as an 8:1 mixture of trans-cis isomers.
