90661-39-5Relevant academic research and scientific papers
A convergent and stereoselective total synthesis of phomolides G and H
Subba Reddy,Sivaramakrishna Reddy,Phaneendra Reddy,Yadav
, p. 501 - 504 (2014/03/21)
A stereoselective total synthesis of phomolides G and H, a polyketide natural products is described. The synthesis involves organocatalytic enantioselective asymmetric epoxidation, C1-Wittig olefination, and ring-closing metathesis as key steps. The use of organocatalytic MacMillan asymmetric epoxidation for the construction of two chiral centers of phomolides G and H makes this approach more attractive. Georg Thieme Verlag Stuttgart New York.
Total syntheses of d-allo-1-deoxynojirimycin and l-talo-1-deoxynojirimycin via reductive cyclization
Chavan, Subhash P.,Dumare, Nilesh B.,Pawar, Kailash P.
, p. 40852 - 40858 (2015/02/05)
Synthesis of a polyhydroxypiperidine framework for l-talo-1-deoxynojirimycin and d-allo-1-deoxynojirimycin was achieved from l-tartaric acid by employing flash dihydroxylation and reductive lactamisation as the key steps. This journal is
DIBAL-mediated reductive transformation of trans-dimethyl tartrate acetonide into ε-hydroxy α,β-unsaturated ester and its derivatives
Tomioka, Takashi,Yabe, Yuki,Takahashi, Tohru,Simmons, Tracy K.
, p. 4669 - 4674 (2011/07/30)
Stepwise, selective DIBAL reduction of the acetonide diester derived from tartaric acid followed by the Horner- Emmons reaction effectively provided desymmetrized hydroxy mono-olefination products in a one-pot operation.
Synthesis of the C3-14 fragment of palmerolide A using a chiral pool based strategy
Lebar, Matthew D.,Baker, Bill J.
experimental part, p. 1557 - 1562 (2010/04/02)
Palmerolide A, a potent and selective inhibitor of melanoma cell growth, is a macrocylic polyketide isolated from the Antarctic tunicate Synoicum adareanum. Palmerolide A targets transmembrane proton pumps, the vacuolar-ATPases, and induces autophagy, but
Structure-based design, synthesis and preliminary evaluation of selective inhibitors of dihydrofolate reductase from Mycobacterium tuberculosis
El-Hamamsy, Mervat H.R.I.,Smith, Anthony W.,Thompson, Andrew S.,Threadgill, Michael D.
, p. 4552 - 4576 (2008/03/12)
Tuberculosis is an increasing threat, owing to the spread of AIDS and to the development of resistance of the causative organism, Mycobacterium tuberculosis, to the currently available drugs. Dihydrofolate reductase (DHFR) is an important enzyme of the folate cycle; inhibition of DHFR inhibits growth and causes cell death. The crystal structure of M. tuberculosis DHFR revealed a glycerol tightly bound close to the binding site for the substrate dihydrofolate; this glycerol-binding motif is absent from the human enzyme. A series of pyrimidine-2,4-diamines was designed with a two-carbon tether between a glycerol-mimicking triol and the 6-position of the heterocycle; these compounds also carried aryl substituents at the 5-position. These, their diastereoisomers, analogues lacking two hydroxy groups and analogues lacking the two-carbon spacing linker were synthesised by acylation of the anions derived from phenylacetonitriles with ethyl (4S,5R)-4-benzyloxymethyl-2,2-dimethyl-1,3-dioxolane-4-propanoate, ethyl (4S,5S)-4-benzyloxymethyl-2,2-dimethyl-1,3-dioxolane-4-propanoate, tetrahydrooxepin-2-one and 2,3-O-isopropylidene-d-erythronolactone, respectively, to give the corresponding α-acylphenylacetonitriles. Formation of the methyl enol ethers, condensation with guanidine and deprotection gave the pyrimidine-2,4-diamines. Preliminary assay of the abilities of these compounds to inhibit the growth of TB5 Saccharomyces cerevisiae carrying the DHFR genes from M. tuberculosis, human and yeast indicated that 5-phenyl-6-((3R,4S)-3,4,5-trihydroxypentyl)pyrimidine-2,4-diamine selectively inhibited M. tuberculosis DHFR and had little effect on the human or yeast enzymes.
De novo enantioselective syntheses of galacto-sugars and deoxy sugars via the iterative dihydroxylation of dienoate
Ahmed, Moinuddin Md.,Berry, Bryan P.,Hunter, Thomas J.,Tomcik, Dennis J.,O'Doherty, George A.
, p. 745 - 748 (2007/10/03)
(Chemical Equation Presented) An efficient route to various sugar lactones has been developed. Key to the overall transformation is the sequential osmium-catalyzed dihydroxylation of 2,4-dienoates. The simplest (one-step/racemic) example of this reaction occurs when the dihydroxylation is performed with aqueous NMO in MeOH. When the first dihydroxylation is performed using the AD-mix procedure, an enantioselective variant results. When a matched AD-mix procedure is used for the second dihydroxylation, an exceedingly diastereo- and enantioselective synthesis of galacto-1,4-lactone results.
Structure elucidation and synthesis of (4S,5S,6Z,8E)-5-hydroxydeca-6,8-dien-4-olide [(S,S)-sapinofuranoue B]-a novel γ-lactone metabolite of acremonium strictum
Clough, Sarah,Raggatt, Mairi E.,Simpson, Thomas J.,Wills, Christine L.,Whiting, Andrew,Wrigley, Stephen K.
, p. 2475 - 2481 (2007/10/03)
The structure of (4S,5S,6Z,8E)-5-hydroxydeca-6,8-dien-4-olide, a novel metabolite of Acremonium strictum, has been established by spectroscopic studies and chemical correlation with the known L-factor. The structure has been confirmed by a total synthesis in which the asymmetric centres at C-4 and C-5 were elaborated from dimethyl L-tartrate and the 6,8-diene moiety was introduced via Stille coupling of (E)-prop-1-enyltributyltin with a (Z)-vinylic iodide. The absolute configurations of sapinofuranones A and B, recently isolated metabolites of Sphaeropsis sapinae, are shown to be the corresponding (4R,5S) and (4R,5R) diastereomers of the A. strictum metabolite.
Acyl Radical Cyclization in Synthesis. Part 4. Tandem Processes: The 7-endo/5-exo Serial Cyclization Approach to Enantiomerically Pure Bicyclodecan-2-ones
Batty, Duncan,Crich, David
, p. 3193 - 3204 (2007/10/02)
Two diastereoisomeric phenylselenoesters of 4,5-dihydroxyhept-6-enoic acid were prepared as their acetonide derivatives from the chiral pool.On treatment with tributyltin hydride and azoisobutyronitrile the erythro isomer cyclized to give meso-4,5-dihydroxycycloheptanone, as its acetonide, in moderate yield whereas under the same conditions the threo-isomer gave a much lower yield of the corresponding C2-symmetric ketone.In the erythro-series an alkyl group at C-7 of the heptenoyl system was found to retard significantly the direct endo-mode cyclisation; however, the cycloheptanone could still be obtained by a rearrangement when the tin hydride concentration was kept to a minimum.A tandem 7-endo/5-exo cyclization system was then constructed and tested, resulting in the formation of all four possible diastereoisomeric biyclodecanones.Further model studies were conducted on the effect of alkyl and alkoxy substituents at C-5 of the heptenoyl radical system on the mode of cyclisation.Alkyl substituents exert a steric effect whilst alkoxy substituents also have a stereoelectronic effect.
Addition of Organocopper Reagents to Cyclic Sulfites or Carbonates of γ,δ-Dihydroxy (E)-α,β-Enoates
Kang, Suk-Ku,Park, Young-Won,Lee, Dong-Ha,Sim, Hyeong-Su,Jeon, Jae-Hoon
, p. 705 - 708 (2007/10/02)
Reaction of cyclic sulfites or carbonates of γ,δ-dihydroxy (E)-α,β-enoates with R2Cu(CN)Li2, BF3; RCu(CN)Li, BF3 (R=Me-, n-Bu-) afforded either diastereoselective SN2' products or reductive elimination product depending on reaction conditions.Addition of R2Cu(CN)Li2, BF3 (R=Me-, n-Bu-) to cyclic sulfite (1) or cyclic carbonate (3) (inverse addition) afforded highly regio-, (E)-stereo- and diastereoselectivity α-alkylation products (6 and 8).By using this methodology, (2S, 5S)-trans-2-methyl-5-hexanolide, the pheromone of the carpenter bee Xylocopa hirutissima was synthesized.
An acyl radical initiated tandem 7-endo/5-exo radical cyclization approach to enantiomerically pure bicyclo[5.3.0]decan-2-ones
Batty,Crich
, p. 875 - 878 (2007/10/02)
The preparation of acetonide derivatives of erythro and threo 4,5-dihydroxyhept-6-enoic acids from the chiral pool is described. The phenylseleno esters derived from these acids undergo cyclization with tributyltin hydride to give mixtures of cyclohexanones and cycloheptanones. The inclusion of the appropriate four carbon side chain at C-7 leads, via a tandem radical cyclization process, to the title compounds in moderate yield.
