共查询到20条相似文献,搜索用时 543 毫秒
1.
Scott Collins James A. Duncan Yoshio Kabe Shu Murakami Satoru Masamune 《Tetrahedron letters》1985,26(24):2837-2840
Reductive coupling of 1--butyl-2,2-dimesityl-1,1,2-trichlorodisilane employing Li-naphthalenide furnishes, on oxygenation or hydrolysis of the reaction mixture, products (-) that may arise from insertion of oxygen into or the addition of water across the Si-Si bonds of 1,3-di--butyl-2,2,4,4-tetramesityltetrasilabicyclo-[1.1.0]butane (). 相似文献
2.
Combination of ()-4--butyldimethylsiloxy-2-cyclopentenone, ()-()-3--butyldimethylsiloxy-1-iodo-1-octene, and 6-methoxycarbonyl-2-hexynal via the tandem organo-copper conjugate addition—aldol reaction procedure leads directly to a 5,6-dehydroprostaglandin E2 derivative, which can be transformed to a variety of chiral primary prostaglandins in a stereoselective manner. 相似文献
3.
4-(N-Alkylimino)methyl-2,6-di--butylphenols (), Schiff bases of 3,5-di--butyl-4-hydroxybenzaldehyde can be oxygenated in the presence of Co(Salpr), a five coordinate Co(II)-Schiff base complex to give N-alkyl-3--butyl-5-formyl-2-hydroxy-2-pivaloyl-1,2-dihydropyridines ( as the main product together with 3-formyl-2,5-di--butyl-2,4-cyclopentadienone () and 2,6-di--butyl-4-formyl-6-hydroxy-4,5-epoxy-2-cyclohexenone (). These products result from dioxygen incorporation into the ortho position of . 相似文献
4.
TiCl4 catalyzes the essentially quantitative coupling of chiral acetals with 1--butoxy-1--butyldimethylsilyloxyethene to generate β-alkoxycarboxylates in which the new asymmetric center is formed with excellent diastereoselection. β-hydroxycarboxylic acids of high ee result from removal of the chiral auxiliary. The procedure has been applied to the synthesis of R-(+)-α-lipoic acid 相似文献
5.
Although the hydrochloride of -4--butyl-1-phenyl--1-(N-piperidyl)cyclohexane crystallizes in the conformation with axial -butyl, it exists as an almost equimolar mixture of the two chair conformers in CD2 Cl2 solution. The position of equilibrium allows one to calculate ΔG°-Bu as ?4.9 kcal/mol. 相似文献
6.
-Butyl or methyl hypoiodite, generated from potassium t-butoxide or sodium methoxide and iodine monochloride, react with olefins via a bridged iodonium ion intermediate giving the -vicinal iodo --butyl or -methyl ethers. 相似文献
7.
Dicobalt octacarbonyl catalyzed silyl-hydroformylation of oxetanes can be controlled by the choice of trialkylsilane. Triethylsilane gives 1,4--silyl ethers while -butyl-dimethylsilane yields silyl enol ethers. 相似文献
8.
6--leukotrienes C and D (3 and 4) have been synthesized unambiguously via the 5(), 6()-epoxide (5,6-) which is isomeric with leukotriene A. These 6--leukotrienes are less active (especially 4) than leukotrienes C and D (1 and 2) and have not been found in substantial quantity in natural SRS sources. 相似文献
9.
The structure of α-costal (1) has been confirmed by an unequivocal total synthesis which makes use of --butyl cyanothiolacetate to facilitate the incorporation of the labile acrolein unit present in the naturally occurring aldehyde. 相似文献
10.
Epoxidation of (2)--butoxycarbonylamino-3-butenol afforded, in a highly stereo-selective manner, a -3,4-epoxy-2-aminobutanol derivative which was successfully converted to the unusual amino acid (+)-galantinic acid in 8 steps regiospecific epoxide ring opening with divinyl cuprate. 相似文献
11.
(R,S)-serine-1-13C was incubated in a culture of cells to produce (S)-trytophan-1-13C. Bromoacetyl bromide-2-13C was converted to bromoacetanilide and cyclization of the anilide, followed by reduction and dehydrogenation furnished indole-3-13C. Indole-15N was synthesized by known sequences. These 13C and 15N isotomers of indole were converted by commercially available, lyophilized . to furnish (S)-tryptophan-γ-13C and (S)-tryptophan-indole-15N, respectively. 相似文献
12.
Andrew Freer Christopher J. Gilmore David D. MacNicol Derek R. Wilson 《Tetrahedron letters》1980,21(12):1159-1162
An X-ray study of the adduct formed by hexakis (--butylphenylthiomethyl)benzene (I) with squalene (II) establishes the first example of channel-type inclusion behaviour for a hexahost molecule, the guest triterpene (II) being observed in a novel conformation controlled by host-guest interactions. 相似文献
13.
A six-step synthesis is reported of -3-amino-2-piperidone-6-carboxylic acid from -homoserine lactone and the --butyl ester on -benzyloxycarbonylaminomalonic acid. Evidence of chiral integrity is discussed. 相似文献
14.
Claudio Fuganti Piero Grasselli Giuseppe Pedrocchi-Fantoni 《Tetrahedron letters》1979,20(26):2453-2454
Feeding experiments with (4) [5-3H;5-14C]-leucine () and with the (4) [5-3H;2-14C]-isomer () show that incorporation into the isoprenylated tryptophan derivative echinuline (), produced by , involves, to a large extent, loss of the fragment enbodying the carbon atom at position 2 of the fed amino acid. 相似文献
15.
Radicals derived from the esters of -hydroxy-2-thiopyridone react smoothly in a concerted reaction with 2-carbethoxy-3--butylhioprop-1-ene to give the corresponding 2-carbethoxyallyl derivatives with shift of the double bond. 相似文献
16.
The superoxo complex [Co(CN)5O2]3- was found to act as a reducing agent towards quinones. One-electron reduction took place with -quinones whereas two-electrons reduction with -quinones. 3,5-Di--butyl--benzoquinone gave the corresponding semiquinone Co(III) complex quantitatively. 相似文献
17.
Fe III- doped K10 montmorillonite combined with 4--butylphenol (10 mol %) is a potent catalytic system for unactivated dienophiles. 相似文献
18.
T. Tanaka N. Okamura K. Bannai A. Hazato S. Sugiura K. Manabe S. Kurozumi 《Tetrahedron letters》1985,26(45):5575-5578
(5)-Prostaglandin E2 methyl ester was synthesized from ()-4--butyldimethylsiloxy-2-cyclopentenone by 2-alkenyloxycarbonylation of the organocopper conjugate-addition adduct followed by intramolecular palladium-catalyzed decarboxylative 2-alkenylation. A ()-2-butenylated cyclopentanone derivative was obtained from either 2-[()- or ()-2-butenyloxy-carbonyl]cyclopentanone derivative under the similar reaction condition. 相似文献
19.
The effect of ultrasonic irradiation (45KHz at 25°C) on the solvolysis of -butyl chloride in aqueous ethanol, -propanol and -butanol is (1) to increase the rate constants in the more alcoholic media and (2) to reduce the m values of these reactions. 相似文献
20.
Oxidation of the complexes -[M(CNR)2(dppe)2] (A) (M = Mo or W; R = Me, But or CH3C6H4-; dppe = Ph2PCH2CH2PPh2) with diiodine or silver (I) salts gives the paramagnetic cations -[M(CNR)2(dppe)2]+, (M = Mo, R = CH3C6H4-; M = W, R = But) and -[M(CNR)2(dppe)2]2+ (M = Mo, R = Me or CH3C6H4-; M = W, R = Me or But). Mixtures of products are generally produced when dichlorine or dibromine are the oxidising agents, however pure salts, the seven-coordinate complex cations [MX(CNC6H4CH3-)2(dppe)2]+ (B, X = Cl or Br) have been isolated. A simple molecular orbital scheme is proposed for complexes (A) and used to discuss their electronic spectra and their oxidation. 相似文献