共查询到20条相似文献,搜索用时 0 毫秒
1.
The reported enzymatic resolution products {acetate of (1S,4aS,8aS)-1,2,3,4,4a,5,6,7,8,8a-decahydro-5,5,8a-trimethyl-2-oxo-trans-naphthalene-1-methanol-2-ethylene acetal} (8aS)-5 (>99% ee)] and [(1R,4aR,8aR)-1,2,3,4,4a,5,6,7,8,8a-decahydro-5,5,8a-trimethyl-2-oxo-trans-naphthalene-1-methanol-2-ethylene acetal (8aR)-4 (98% ee) were converted to (+)-alpha-polypodatetraene (1) and methyl (5R,10R,13R)-labda-8-en-15-oate (2), respectively. For the synthesis of (5R,10R,13R)-2, chiral isoprene congener (3S)-26 corresponding to the right part of 2 was synthesized based on the lipase-assisted resolution of (+/-)-2-methyl-3- (p-methoxyphenyl)propanol (17). 相似文献
2.
3.
The crystal structure of C15 H13NO5Te was determined from X-ray diffractometer data. The unit cell is triclinic (Bī): a = 17.118(5), b = 7.402(2), c = 12.225(2) Å, α = 87.96(1), β = 93.31 (1), γ = 92.13(2)° at 22°C, Z = 4/cell, and the conventional R = 0.025 for 2497 independent reflections. The molecule is folded along the Te-ring oxygen axis (135° ). The average Te-ring carbon distance is 2.101 Å, the Te-acetonyl carbon distance is 2.129 Å and the average C-ring oxygen distance is 1.388 Å. The acetonyl group and phenyl rings have normal distances and angles, and the nitrate group is nearly regular, with Te…ONO2 = 2.775 Å. The coordination around Te is that of an extremely distorted trigonal bipyramid, with apical positions occupied by one ring carbon and the ONO2 group (167.4°), and two axial positions occupied by the acetonyl carbon and the other ring carbon (94.6°). Coordinates of all hydrogen atoms were determined. 相似文献
4.
《结构化学》1992,(5)
<正> The title com pound (HHOMP) has been synthesized with the pho-toinduced condensation of acetone and pyrrole in the presence of iodoaromatic hydrocarbons, and its molecular and crystal structures have been determined by X-ray analysis. C28H36N4, Mr = 428. 63, triclinic; space group P1; a =10. 165(3), b = 10. 185(2), c=13. 012(3)(?); α=85. 41(2), β=67. 84(2), γ= 89. 75(2)°; V = 1243 (?)3; Z = 2; D = 1. 145g. cm-3; μ= 0. 635cm-1; F (000) = 464. Although the HHOMP molecule twists, it is found that the four nitrogen atoms are still in a plane. 相似文献
5.
A synthesis of methyl 2-oxo-5-vinyl-tetrahydrofuran-3-carboxylate involving five synthetic steps from commercially available 3,4-dihydroxybutene is reported. 相似文献
6.
Sarcophytol-A precursor (10) has been convergently synthesized by a route, which employed double bond migration reaction (d) and phase transfer catalytic (PTC) coupling reaction (e) as the key steps. 相似文献
7.
The synthesis of a prostaglandin E1 analog, 7-oxo-8-aza-10a-homoprost-13-enoic acid, is reported. 相似文献
8.
P. A. Zoretic N. D. Sinha T. Shiah T. Maestrone B. Branchaud 《Journal of heterocyclic chemistry》1978,15(6):1025-1026
The synthesis of a prostaglandin E1 analog, 8-aza-15-hydroxy-7-oxo-12S-13E-prostenoic acid, is reported. 相似文献
9.
Stereoselective synthesis of 15,16-didehydro coriolic acid, starting from pent-2-en-4-yn-1-ol is described. 相似文献
10.
D. Bailey D. Tirrell O. Vogl 《Journal of polymer science. Part A, Polymer chemistry》1976,14(11):2725-2747
Four new derivatives of 5-vinylsalicylic acid were prepared and their homopolymerization and copolymerization with acrylic acid and methacrylic acid investigated. Methyl 5-vinylsalicylate was prepared in a six-step synthesis from methyl salicylate in an overall yield of 35%. Acetylation in the last step yielded methyl 5-vinylacetylsalicylate. Hydrolysis of methyl 5-vinylsalicylate gave 5-vinylsalicylic acid which was acetylated to 5-vinylacetylsalicylic acid (5-vinyl aspirin). The 5-vinyl-substituted salicylic acid derivatives could be readily homopolymerized and copolymerized with acrylic acid and methacrylic acid to give various compositions of copolymers. It is worth noting that even the monomers with free phenol groups could be readily polymerized with azobisisobutyronitrile as radical initiator to high molecular weight polymers without interference of the phenolic OH group. 相似文献
11.
12.
Katsumi NishimuraHiroshi Tsubouchi Masashi OnoTomoharu Hayama Yasuo NagaokaKiyoshi Tomioka 《Tetrahedron letters》2003,44(11):2323-2326
The asymmetric reaction of ω-oxo-α,β-unsaturated esters with lithium chiral thiolates afforded the Michael-aldol tandem cyclization products in high yield and good stereoselectivity. Reductive desulfurization gave the corresponding optically pure 2-hydroxycycloalkanecarboxylates. 相似文献
13.
14.
The folate analogue, 10-thia-5-deazafolic acid, was obtained via a multistep synthetic sequence beginning with the known intermediate, 2,4-diaminopyrido[2,3-d]pyrirnidine-6-carboxaldehyde. Reduction of this aldehyde with sodium borohydride gave 2,4-diamino-6-(hydroxymethyl)pyrido[2,3-d]pyrimidine, which when heated in base gave 2-amino-3,4-dihydro-6-(hydroxymethyl)-4-oxopyrido[2,3-d]pyrimidine. Treatment of the latter compound with phosphorus tribromide in tetrahydrofuran afforded 2-amino-6-(bromomethyl)-3,4-dihydro-4-oxopyrido[2,3-d]pyrimidine, thus constituting the first successful synthesis of this elusive intermediate. The aforementioned bromomethyl compound reacted smoothly with the sodium salt of ethyl 4-mercaptobenzoate, and the resulting ester was saponified to give 10-thia-5-deazapteroic acid. Conventional peptide bond coupling to di-tert-butyl L-glutamate followed by treatment with trifluoroacetic acid afforded the target compound in respectable yield. Attempts to prepare its 5,6,7,8-tetrahydro derivative by catalytic hydrogenation were unsuccessful. 相似文献
15.
16.
The 13C NMR chemical shifts for 4-oxo-1,3-dioxolane (1) and its all methyl-substituted derivatives (2-10) as well as for 5-oxo-1,3-oxathiolane (11) and its nine alkyl-substituted derivatives (12-20) are reported. The magnitude and variety of the substituent effects are in accordance with the envelope conformations in which the oxygen or sulfur atom locates at the tip of the envelope as postulated on the basis of earlier data. 相似文献
17.
合成了两个具有三个羟基的新型主体分子反式-5,10,15-三芳烃-5,10,15-三羟基-1-氢-三苯并[a,f,k]三茚(芳基分别为苯基和-萘基),并通过从头算对其及其异构体的结构进行了分析,结果发现当芳基为苯基时,其顺式异构体分子印环中所有原子不完全处于共平面,而其反式异构体和1-萘基的顺反异构体均处于共平面。 相似文献
18.
David T. Connor Roderick J. Sorenson Francis J. Tinney Wiaczeslaw A. Cetenko Joseph J. Kerbleski 《Journal of heterocyclic chemistry》1982,19(5):1185-1188
A general synthesis of 10-Oxo-10H-pyrido[1,2-a]thieno[3,4-d]pyrimidines and 10-Oxo-10H-pyrido[1,2-a]-thieno[3,2-d]pyrimidines is described. Methyl tetrahydro-4-oxo-3-thiophenecarboxylate ( 13 ) was condensed with 6-aminonicotinic acid ( 18 ) to give 3,10-dihydro-10-oxo-1H-pyrido[1,2-a]thieno[3,4-d]pyrimidine-7-carboxylic acid ( 19 ). Treatment of 19 successively with chlorotrimethylsilane, N-chlorosuccinimide and water gave 10-oxo-10H-pyrido[1,2-a]thieno[3,4-d]pyrimidine-7-carboxylic acid ( 17 ). Methyl tetrahydro-3-oxo-2-thiophenecarboxylate ( 21 ) was converted to 10-oxo-10H-pyrido[1,2-a]thieno[3,2-d]pyrimidine-7-carboxylic acid ( 25 ) by an analogous route. 相似文献
19.
Frank Kienzle 《Helvetica chimica acta》1980,63(3):563-567
Note on the Synthesis of (E)-12-Hydroxy-10-heptadecenoic Acid, (5E, 10E)-12-Hydroxy-5, 10-heptadienoic Acid and (5Z, 10E)-12-Hydroxy-5,10-heptadienoic Acid The syntheses of two heptadecadienoic and one heptadecenoic acid, compounds which formally may be derived from prostaglandin-like molecules by removal of a C3-fragment from the five-membered ring, are described. 相似文献
20.
A phosphorus-containing monomer(10-oxo-10-hydro-9-oxa-10λ~5-phosphaphenanthrene-10-yl)-methyl acrylate(M_1) was copolymerized with styrene to give a potential flame retardant copolymer of high thermal stability.The structures of monomer and copolymer were characterized by FT-IR and ~1H NMR measurements.The reactivity ratios for free-radical of the monomer(M_1) and styrene(M_2) were studied.The calculated results are as follows:r_1=0.225,r_2=0.503;Q_1=0.413,e_1= 0.476;azeotropic point = 0.37.TGA and DTG c... 相似文献