- New strategy for production of primary alcohols from aliphatic olefins by tandem cross-metathesis/hydrogenation
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Primary alcohols are widely used in industry as solvents and precursors of detergents. The classic methods for hydration of terminal alkenes always produce the Markovnikov products. Herein, we reported a reliable approach to produce primary alcohols from terminal alkenes combining with biomass-derived allyl alcohol by tandem cross-metathesis/hydrogenation. A series of primary alcohol with different chain lengths was successfully produced in high yields (ca. 90percent). Computational studies revealed that self-metathesis and hydrogenation of substrates are accessible but much slower than cross-metathesis. This new methodology represents a unique alternative to primary alcohols from terminal alkenes.
- Jia, Ruilong,Zuo, Zhijun,Li, Xu,Liu, Lei,Dong, Jinxiang
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supporting information
p. 1525 - 1529
(2019/11/11)
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- Enantiospecific total synthesis of the squalene synthase inhibitors (-)-CJ-13,982 and its enantiomer from a common intermediate
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The total syntheses of both the natural and unnatural enantiomers of the alkyl citrate natural product CJ-13,982 (1) from the common d-ribose-derived acid 6 are described.
- Sturgess, Dayna,Chen, Zongjia,White, Jonathan M.,Rizzacasa, Mark A.
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p. 234 - 239
(2018/03/21)
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- Extended structural modulation of bio-inspired chiral lipidic alkynylcarbinols as antitumor pharmacophores
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The chiral alkynylcarbinol motif typically found in natural marine products, has been the subject of intense research activity for its pharmacophoric properties, in particular cytotoxicity against tumor cell lines. In a chemical synthesis-driven four-parameter structure-activity relationship (SAR) study from the (S,E)-eicos-4-en-1-yl-3-ol natural reference 1, the (S)-dialkynylcarbinol unit of the non-natural dehydro derivative 2 emerged as an unprecedented anti-tumoral pharmacophore. An extended study of lipidic alkynylcarbinol pharmacophores is presented, addressing additional structural parameters: Z→E isomerization of the alkenyl carbinol substituent of 1, variation of the lipidic chain length of 2 (C3n, n=3, 4, 6), oxidation or substitution of the carbinol unit of 2 (to ketone, tertiary methylcarbinol, or methylether), cyclomethylenation of the double bond of 1. The synthesis of these analogues is described, including the preparation of enantio-enriched chiral alkynylcarbinol derivatives using a modified Carreira procedure for Zn-mediated addition of (trialkylsilyl)acetylene substrates to ynals in the presence of (-)- or (+)-N-methylephedrine. Preliminary cytotoxicity evaluation of 12 new products against the HCT 116 tumor cell line are finally reported and the results compared with those obtained for 1 and 2. These observations support and refine the relevance of the pharmacophoric character of secondary DAC units.
- Listunov, Dymytrii,Billot, Chelmia,Joly, Etienne,Fabing, Isabelle,Volovenko, Yulian,Génisson, Yves,Maraval, Valérie,Chauvin, Remi
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p. 7920 - 7930
(2015/09/15)
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- Synthesis of 6-Hydroxysphingosine and α-Hydroxy Ceramide Using a Cross-Metathesis Strategy
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(Chemical Equation Presented) In this paper, a new synthetic route toward 6-hydroxysphingosine and α-hydroxy ceramide is described. The synthesis employs a cross-metathesis to unite a sphingosine head allylic alcohol with a long-chain fatty acid alkene that also bears an allylic alcohol group. To allow for a productive CM coupling, the sphingosine head allylic alcohol was protected with a cyclic carbonate moiety and a reactive CM catalyst system, consisting of Grubbs II catalyst and CuI, was employed.
- Wisse, Patrick,De Geus, Mark A. R.,Cross, Gen,Van Den Nieuwendijk, Adrianus M. C. H.,Van Rooden, Eva J.,Van Den Berg, Richard J. B. H. N.,Aerts, Johannes M. F. G.,Van Der Marel, Gijsbert A.,Codée, Jeroen D. C.,Overkleeft, Herman S.
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p. 7258 - 7265
(2015/07/27)
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- De novo asymmetric syntheses of muricatacin and its analogues via dihydroxylation of dienoates
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A short and highly efficient route to both enantiomers of muricatacin as well as the C-5-epimer has been developed. The key to the overall transformation is the highly regio- and enantioselective Sharpless asymmetric dihydroxylation of an (E,Z)-dienoate. The highly efficient stereoselective synthesis prepares (-)-muricatacin in seven steps and 66% overall yield.
- Ahmed, Md. Moinuddin,Cui, Hu,O'Doherty, George A.
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p. 6686 - 6689
(2007/10/03)
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- The first total synthesis of the 6-hydroxy-4E-sphingenines
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Ceramides containing the 6-hydroxy-4E-sphingenines, previously unknown long-chain bases, have recently been found in human skin. A total synthesis of 6-hydroxy-4E-sphingenines has been achieved.
- Yadav,Geetha,Raju, A. Krishnam,Gnaneshwar,Chandrasekhar
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p. 2983 - 2985
(2007/10/03)
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- Electrophilic selenocyclization in 2-ene-1,5-diol systems: Unexpected oxetane vs. tetrahydrofuran formation
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Electrophile-induced cyclization of (E)- and (Z)-2-ene-1,5-diols to tetrahydrofurans and oxetanes is described. Significant differences between the present report and previous work have been noted. A tentative model is proposed.
- Van De Weghe, Pierre,Bourg, Stéphane,Eustache, Jacques
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p. 7365 - 7376
(2007/10/03)
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- A simple synthetic method for chiral 1,2-epoxides and the total synthesis of a chiral pheromone epoxide
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Chiral 1,2-epoxyalkan-3-ol tosyl esters 4a-h were successfully synthesized from alkynols or allyl chlorides in three steps using Sharpless AD reaction as a key step in good yields. The chiral insect pheromone epoxide (6Z,9S,10R)-9,10-epoxyhenicos-6-ene 9 was thus smoothly synthesized from the corresponding key intermediate 4g.
- Zhang, Zhi-Bo,Wang, Zhi-Min,Wang, Yu-Xiu,Liu, Huan-Quan,Lei, Gui-Xin,Shi, Min
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- A facile synthetic method for chiral 1,2-epoxides and the total synthesis of chiral pheromone epoxides
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Chiral 1,2-epoxy-3-alkanol tosylates were successfully synthesized from alkynols in three steps using the Sharpless AD reaction as a key step in good yields. Two chiral insect pheromone epoxides were smoothly obtained from the corresponding key intermediate.
- Zhang, Zhi-Bo,Wang, Zhi-Min,Wang, Yu-Xiu,Liu, Huan-Quan,Lei, Gui-Xin,Shi, Min
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p. 837 - 840
(2007/10/03)
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- Structure determination of an endogenous sleep-inducing lipid, cis-9-octadecenamide (oleamide): A synthetic approach to the chemical analysis of trace quantities of a natural product
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The pursuit of endogenous sleep-inducing substances has been the focus of an extensive, complicated body of research. Several compounds, including Δ-sleep-inducing peptide and prostaglandin D2, have been suggested to play a role in sleep induction, and yet, the molecular mechanisms of this physiological process remain largely unknown. In recent efforts, the cerebrospinal fluid of sleep-deprived cats was analyzed in search of compounds that accumulated during sleep deprivation. An agent with the chemical formula C18H35NO was found to cycle with sleep-wake patterns, increasing in concentration with sleep deprivation and decreasing in amount upon recovery sleep. Since the material was generated in minute quantities and only under the special conditions of sleep deprivation, efforts to isolate sufficient material for adequate characterization, structure identification, and subsequent detailed evaluation of its properties proved unrealistic. With the trace amounts of the impure endogenous compound available, extensive MS studies on the agent were completed, revealing key structural features of the molecule including two degrees of unsaturation, a long alkyl chain, and a nitrogen substituent capable of fragmenting as ammonia. Additionally, HPLC traces suggested a weak UV absorbance for the unknown material. With this data in hand and encouraged by the relatively small size of the molecule, MW = 281, a synthetic approach toward the structural identification of the natural compound was initiated. Herein, we report the full details of the synthesis and comparative characterization of candidate structures for this endogenous agent that led to the unambiguous structural correlation with synthetic cis-9-octadecenamide.
- Cravatt, Benjamin F.,Lerner, Richard A.,Boger, Dale L.
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p. 580 - 590
(2007/10/03)
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- Synthesis of (4R,5R)-Muricatacin and its (4R,5S)-Analog by Sequential Use of the Photo-Induced Rearrangement of Epoxy Diazomethyl Ketones
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The naturally occuring δ-hydroxy-γ-lactone (4R,5R)-muricatacin and its nonnatural (4R,5S)-analog are synthesized.The starting achiral allylic alcohols are converted into α,β-epoxy diazomethyl ketones followed by a stereospecific irradiation reaction of these compounds to give 4-hydroxy-2-alkene esters.Using this method in a sequential manner a successive introduction of stereogenic centers is realized, resulting in enantiopure 4,5-dihydroxy-2-alkene esters.These alcohols are converted into the δ-hydroxy-γ-lactone muricatacin.
- Aar, Marcel P. M. van,Thijs, Lambertus,Zwanenburg, Binne
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p. 11223 - 11234
(2007/10/02)
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- C-1 Reactivity of 2,3-Epoxy Alcohols via Oxirane Opening with Metal Halides: Application and Synthesis of Naturally Occuring 2,3-Octanediol, Muricatacin, 3-Octanol, and 4-Dodecanolide
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The C-1 reactivity of 2,3-epoxy alcohols and derivatives has been examined thoroughly.In the first approach a rearrangement opening of 2,3-epoxy alcohols with LiI leads to 1-iodo 2,3-diols with erythro or threo stereochemistry starting from trans or cis epoxy alcohols.Subsequent coupling with a carbon nucleophile can lead to a series of vicinal diols with predicted relative and absolute stereochemistry: the described methodology has been applied to the asymmetric synthesis of the naturally occuring (S,S)-2,3-octanediol and (R,R)-muricatacin.The second approach, starting from easily available tosyloxy epoxides, leads to the highly regioselective opening of the oxirane ring with Li halides.The 3-iodohydrins obtained can be reduced to the corresponding 1-(tosyloxy)alkan-2-ols and then coupled with common carbon nucleophiles to afford, in high yields, optically active alcohols.This methodology has been applied to the asymmetric synthesis of naturally occuring pheromones like 3(R)-octanol and 4(R)-dodecanolide.
- Bonini, Carlo,Federici, Chiara,Rossi, Leucio,Righi, Giuliana
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p. 4803 - 4812
(2007/10/02)
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- REGIOSPECIFIC RING OPENING OF α,β-EPOXYSILANES WITH SILICON TETRAFLUORIDE AND APPLICATION TO THE SYNTHESIS OF FLUOROALKENES
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α,β-Epoxysilanes undergo the ring opening-fluorination with silicon tetrafluoride in the presence of diisopropylethylamine and water to give β-fluoro-β-silyl alcohols specifically, and the subsequent olefination with potassium hexamethyldisilazide affords fluoroalkenes in good yield.
- Shimizu, Makoto,Yoshioka, Hirosuke
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p. 967 - 970
(2007/10/02)
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