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1.
Tetsuya Sengoku 《Tetrahedron》2008,64(35):8052-8058
An enantiomerically and diastereomerically pure route has been developed for the first asymmetric synthesis of (1S,2R,3R,5R,7aR)- and (1S,2R,3R,5S,7aR)-1,2-dihydroxy-3,5-dihydroxymethylpyrrolizidine, hyacinthacine B1 and B2, featuring efficient and stereodefined elaboration via the asymmetric dihydroxylation (AD) of the functionalized homochiral pyrrolidine derivative prepared from (S)-(−)-2-pyrrolidone-5-carboxylic acid. 相似文献
2.
The synthesis of (1R,2S)- and (1S,2R)-1-amino-2-(hydroxymethyl)cyclopropanephosphonic acids was accomplished using different strategies. The (1R,2S)-stereoisomer could be efficiently obtained by the cyclopropanation of ethyl diethoxyphosphorylacetate with the cyclic sulfate derived from (S)-3-benzyloxy-1,2-propandiol as a key step. The (1S,2R)-stereoisomer was synthesized from a readily available (1S,5R)-3-oxabicyclo[3.1.0]hexan-2-on-1-phosphonate. 相似文献
3.
Amanda C FergusonRobert M Adlington Domnic H MartyresPeter J Rutledge Andrew CowleyJack E Baldwin 《Tetrahedron》2003,59(41):8233-8243
A route has been developed which allows synthesis of novel cyclobutanone analogues of penicillin. This is illustrated by the synthesis of (1R,4R,5R,5′R,7S)-(1b) and (1S,4S,5S,5′R,7R)-7-[5′-amino-5′-carboxy]pentanamido]-2-thiabicyclo[3.2.0]heptan-6-one-4-carboxylate (1a), an analogue of penicillin N. The key steps in the synthesis were the formation of the bicyclic structure via a [2+2] cycloaddition and the introduction of nitrogen at C7 via an intramolecular nitrene insertion. 相似文献
4.
José M. Otero José C. Barcia Cristian O. Salas Pablo Thomas Juan C. Estévez Ramón J. Estévez 《Tetrahedron》2012,68(5):1612-1621
A strategy for the synthesis of the novel (6bR,7R,8S,9S,10S,10aR)-8-(benzyloxy)-7,9,10-trihydroxy-6b,7,8,9,10,10a-hexahydro-11H-benzo[a]carbazole-5,6-dione is reported. The key steps were the Michael addition of 2-hydroxy-1,4-naphthoquinone to 1-nitrocyclohexene or 3-O-benzyl-5,6-dideoxy-1,2-O-isopropylidene-6-nitro-α-d-xylo-hex-5-enefuranose and the diastereoselective intramolecular Henry reaction of 3-O-benzyl-5,6-dideoxy-5-C-(3′-hydroxy-1′,4′-naphthoquinon-2′-yl)-1,2-O-isopropylidene-6-nitro-α-d-glucofuranose to give the key (1S,2S,3S,4R,5R,6R)-3-(benzyloxy)-1,2,4-trihydroxy-5-(3′-hydroxy-1′,4′-naphthoquinon-2′-yl)-6-nitrocyclohexane. When 2-hydroxy-1,4-naphthoquinone was replaced by (1,4-dimethoxynaphthalen-2-yl)lithium, the novel (1R,2S,3S,4R,4aS,11bS)-2-(benzyloxy)-1,3,4-trihydroxy-1,2,3,4,4a,5-hexahydro-11bH-benzo[b]carbazole-6,11-dione was obtained. 相似文献
5.
Nicola D’Antona Raffaele Morrone Paolo Bovicelli Giovanni Gambera David Kubáč Ludmila Martínková 《Tetrahedron: Asymmetry》2010,21(20):2448-2454
A new route to synthesize cyclophellitol and epi-cyclophellitol from racemic starting materials in enantiopure forms has been developed. The synthesis involves a multi-enzymatic biotransformation pathway of the novel cyano-cyclitol (1R,4S,5R,6R)/(1S,4R,5S,6S)-4,5,6-trihydroxycyclohex-2-enecarbonitrile by a cooperative use of lipase, nitrile hydratase, and amidase. 相似文献
6.
《Tetrahedron: Asymmetry》2007,18(23):2787-2790
The enantioselective synthesis of (R)- and (S)-1-amino-3-hydroxypropylphosphonic acid, the phosphonate analogues of (S)- and (R)-homoserine, has been accomplished in four steps and good overall yield starting from diethyl (3R,5R)- or (3S,5S)-5-(hydroxymethyl)-2-[(S)-1-phenylethyl]isoxazolidinyl-3-phosphonate, respectively. 相似文献
7.
《Tetrahedron: Asymmetry》2005,16(18):3059-3069
The paper reports the first enantioselective synthesis of all the possible collagen reduced cross links as described: (2S,2′S,5R)- and (2S,2′S,5S)-5-hydroxylysinonorleucine 3a and 3b, (2S,2′S,5R,5′R)-5,5′-dihydroxylysinonorleucine 4a, (2S,2′S,5R,5′S)-5,5′-dihydroxylysinonorleucine 4b and (2S,2′S,5S,5′S)-5,5′-dihydroxylysinonorleucine 4c. The Williams’ glycine template methodology was used both for the introduction of a stereogenic at the α-position and for an easy protection of the amino acidic functionalities during the synthesis of the dimeric amino acids. 相似文献
8.
《Tetrahedron: Asymmetry》2001,12(15):2099-2102
A synthesis of the enamine (−)-(1′S)-5-ethyl-1-(1′-phenylethyl)-1,2,3,4-tetrahydropyridine 4 and its application in a synthesis of (−)-(1′S,4aS,8aR)- and (+)-(1′S,4aR,8aS)-4a-ethyl-1-(1′-phenylethyl)-octahydroquinolin-7-ones 5 and 6 is described. In addition, an X-ray study of 6 is reported. Finally, the preparation of (+)-(4aS,8aR)-4a-ethyl-octahydroquinolin-7-one 7 is described. 相似文献
9.
Takeshi Yamamoto Hideo UjiharaShinya Watanabe Makoto HaradaHiroyuki Matsuda Toshimitsu Hagiwara 《Tetrahedron》2003,59(4):517-524
The synthesis characterized by cationic olefin cyclizations accomplished using ketone enol esters and odor of novel (1R,6S)- and (1S,6R)-2,2,6-trimethylcyclohexyl methyl ketones (5) are described. The stereoselective syntheses of (E)-(1R,6S)- and (E)-(1S,6R)-1-(2,2,6-trimethylcyclohexyl)-2-buten-1-one (6) and (1R,6S)-ethyl 2,2,6-trimethylcyclohexylcarboxylate (7), useful raw materials for flavor and fragrance, starting from the (1R,6S)- and (1S,6R)-5 are also described. 相似文献
10.
As shown by synthesis and enantioselective gas chromatography, males and females of the caddisfly species Potamophylax latipennis and Potamophylax cingulatus produce (1R,3S,5S,7S)-1-ethyl-3,5,7-trimethyl-2,8-dioxabicyclo[3.2.1]octane, while Glyphotaelius pellucidus produces 1,3-diethyl-4,6-dimethyl-2,7-dioxabicyclo[2.2.1]heptane, having either the (1S,3S,4R,6S) or (1R,3R,4S,6S)-configuration. As shown by electrophysiological investigations, the compounds are perceived by the antennae of both sexes. 相似文献
11.
(+)-MK7607 is a patented naturally occurring unsaturated pseudo-carbasugar possessing herbicidal activity. We present herein the first synthesis of the 5-fluorinated analogue (1S, 2S, 3R, 4R)-5-fluoro-6-(hydroxymethyl)cyclohex-5-ene-1,2,3,4-tetrol as well as that of two related compounds, namely its 1-epimer and its 6-deoxy derivative. 相似文献
12.
Rakesh K. Singh Neelima Sinha Sanjay Jain Mohammad Salman Nitya Anand 《Tetrahedron》2005,61(37):8868-8874
Making use of amide activation, a convenient and short path synthesis of optically pure ω-heterocyclic-β-amino acids has been achieved from (1R,3R)- and (1R,3S)-5-oxo-1-(1-phenyl-ethyl)-pyrrolidine-3-carboxylic acid methyl ester. The key step of the synthesis involves a regiospecific ring-chain-transformation of the enaminones when subjected to 1,2-binucleophilic attacks. The method is illustrated by the synthesis of (2R)-/(2S)-2-aminomethyl-3-(1-aryl-/1,5-diaryl-1H-pyrazol-3-yl)-propionic acid. 相似文献
13.
Gabriella Benedek Márta Palkó Edit Wéber Tamás A. Martinek Enikő Forró Ferenc Fülöp 《Tetrahedron: Asymmetry》2009,20(19):2220-2225
An efficient method for the synthesis of (1S,2R,4R,5S)- and (1R,2R,4R,5S)-2-amino-4,5-dihydroxycyclohexanecarboxylic acids (?)-6 and (?)-9 and (1R,2R,3S,4R)- and (1S,2R,3S,4R)-2-amino-3,4-dihydroxycyclohexanecarboxylic acids (?)-15 and (?)-18 was developed by using the OsO4-catalyzed oxidation of Boc-protected (1S,2R)-2-aminocyclohex-4-enecarboxylic acid (+)-2 and (1R,2S)-2-aminocyclohex-3-enecarboxylic acid (+)-11. Good yields were obtained. The stereochemistry of the synthesized compounds was proven by NMR spectroscopy. 相似文献
14.
1R,2S,5R,8R; 1R,2S,5R,8S; 1S,2S,5R,8R; and 1S,2S,5R,8S-Iridodials have been prepared in five steps from 4aS,7S,7aR and 4aS,7S,7aS-nepetalactones, major components of catnip oil. 1R,2S,5R,8R-Iridodial has been identified as a male-produced male-aggregation pheromone for Chrysopa oculata, the first pheromone of any kind identified for lacewings. 相似文献
15.
Fernando Fernández Amalia M. Estévez Juan C. Estévez Ramón J. Estévez 《Tetrahedron: Asymmetry》2009,20(6-8):892-896
The first total synthesis of a new enantiopure polyhydroxylated cyclopentyl β-amino acid [methyl (1S,2R,3S,4R,5S)-2-benzyloxy-5-benzyloxycarbonylamino-3-hydroxy-4-methoxycyclopentanecarboxylate] was achieved according to our recent novel strategy for the transformation of nitrohexofuranoses into cyclopentylamines. This approach is based on an intramolecular cyclization leading to 2-oxabicyclo[2.2.1]heptane derivatives. Epimerization of this amino acid derivative to methyl (1S,2R,3R,4R,5S)-2-benzyloxy-5-benzyloxycarbonylamino-3-hydroxy-4-methoxycyclopentanecarboxylate constitutes the first example of the preparation of one of the members of this family of amino acids with a stereochemistry that is not compatible with the above key cyclization step. 相似文献
16.
Noriaki Moriyama Yoshihiro Matsumura Masami Kuriyama Osamu Onomura 《Tetrahedron: Asymmetry》2009,20(23):2677-2687
A new method using electrochemical oxidation and/or OsO4 oxidation has been used for the stereoselective synthesis of 2,3,6-trihydroxylated (5S)-piperidine derivatives. The electrochemical method was successively used for the conversion of N-protected piperidines to N-protected 1-methoxypiperidines and for the conversion of 2,3-didehydro-1-methoxypiperidine derivatives to 2,3-trans-1,2,3-triacetoxypiperidine derivatives. These triacetates were easily transformed into (2S,3S)-6-triacetoxy-(5S)-methylpiperidine and (2R,3R)-6-triacetoxy-(5S)-methylpiperidine. In addition, the 2,3-cis-dihydroxylation of 2,3-didehydro-1-methoxypiperidine derivatives with OsO4 afforded (2R,3S)-6-triacetoxy-(5S)-methylpiperidine and (2S,3R)-6-triacetoxy-(5S)-methylpiperidine. 相似文献
17.
A convenient optically active synthesis of (3aS,5R,6aR)-5-hydroxy-hexahydrocyclopenta[b]furan, a high-affinity nonpeptidyl ligand for HIV-1 protease inhibitor 2, is described. The synthesis utilizes commercially available (1R,5S)-(+)-2-oxabicyclo[3.3.0]oct-6-en-3-one as the starting material and oxymercuration or bromohydrin reaction as the key step. Enantiopure ligand was converted to protease inhibitor 2. 相似文献
18.
A stereoselective synthesis of highly optically pure enantiomers of δ-multistriatin [(1S,2S,4S,5R)-2,4-dimethyl-5-ethyl-6, 8-dioxabicyclo[3.2.1)octane and its antipode] was accomplished starting from tartaric acid enantiomers. 相似文献
19.
《Tetrahedron: Asymmetry》1999,10(20):3999-4007
This report describes the synthesis of enantiomerically pure (1S,3S,4R)- and (1S,3R,4R)-3-hydroxy-7-azabicyclo[2.2.1]heptane-1-carboxylic acids, two new conformationally constrained 4-hydroxyprolines, using a straightforward synthetic route and starting from (−)-8-phenylmenthyl 2-acetamidoacrylate. The easy transformation of the pure (1S,3S,4R)-3-hydroxy-7-azabicyclo[2.2.1]heptane-1-carboxylic acid into (1R,4S)-N-Boc-7-azabicyclo[2.2.1]heptan-2-one constitutes a new formal synthesis of (+)-epibatidine. 相似文献
20.
《Tetrahedron: Asymmetry》2005,16(9):1611-1614
A chiron approach for the synthesis of (1R,2R,5S,7S)-2-hydroxy-exo-brevicomin 1, a component of the volatiles obtained from male mountain pine beetles, Dendroctonus ponderosae has been achieved. Our synthesis started with commercially available d-ribose and involves a Wittig olefination, an acid catalyzed one pot hydrogenation and the internal acetalization as key steps. 相似文献