Dimethylsilyl ethyl

Tris(2,2-dimethylethyl)triphosphirane, 3570 Tris(dimethylfluorosilylmethyl)borane, 3218 Tris [ 1 -(dimethylsilyl)ethyl]borane, 3578b Tris(ethylthio)cyclopropenium perchlorate, 3173 Tris(hydroxymethyl)methylamine, 1725 f Trisilane, 4574... 

C,, H2c,N04SSi 106560-32-1) see Faropenem sodium [15-[lo(45, 6S ),2a,6p,8P,8att]]-4-n(l,1-dimethyl-ethyl)dimethylsilyl]oxy]-6-[2-(lA6,7,8,8a-hexahydro-8-hydroxy-2,6-dimethyl-l-naphthalenyl)ethyl]tetrahydro-2ff-pyran-2-one... 

However, this multistep procedure is experimentally complex. A simpler variation described in 199127 consists of the reaction of an aldehyde and a nitro compound in the presence of triethylamine, TBAF and tert-butyl-dimethylsilyl chloride. Under these conditions, nitro sugars are obtained in good yieds and higher diastereoselectivities than those afforded by the standard conditions. This procedure was used in several synthesis of 2-nitro-2-deoxyaldoses, as for the condensation of l,l-diethoxy-2-nitroethane and l,2 3,4-di-0-isopropylidene-a-D-galacto-hexodialdo-l,5-piranose.28 More recently, it was applied to the addition of ethyl nitroacetate to the D-glucose derived aldehyde 18, to give nitro sugar derivatives 26, key precursors of polysubstituted cyclohexane a-amino acids (Scheme 10).29... 

C19H51N3Si4, 1,3-Trisilanediamine, NJf-bis(l, 1-dime thylethyl)-2-[[(l,1-dime thyl-ethyl)amino]dimethylsilyl]-l,l,2,3,3-pentam ethyl-, [162898-51-3], 32 139 10... 

Treatment of ethyl l- 2-[(tm-butyl, dimethylsilyl)oxy]-l-phenylethyl -6-alkylpiperidine-2-carboxylates with 10% HF in MeCN afforded diastereo-meric mixtures of 4-phenyl-6-substituted perhydropyrido[2,l-c][l,4]oxazin-1-ones (94JOC3769). Dieckmann cyclization of ethyl 4-(3-ethoxy-carbonylpropyl)morpholine-3-carboxylate with ferf-BuOK in Et20 and subsequent ester hydrolysis and decarboxylation furnished perhydropy-rido[2,l-c][l,4]-oxazin-9-one (82EUP57536 92BMC1293). Mild acidic hydrolysis of the nitrile moiety of amino nitrile 185 gave pyrido[2,l-c][l,4]ox-azin-l-one 60 (96TL4001). 

Dimethylsilyl chloride and diethylsilyl chloride reacted with lithium ethanetellurolate to give dialkylsilyl ethyltellurium derivatives2. With ethylsilyl dichloride, ethylsilylene bis[ethyl tellurium] was obtained1 and with trichlorosilane, tris ethyltelluro]silane2. 

Ac, acetyl AIBN, azobis(isobutanonitrile) All, allyl AR, aryl Bn, benzyl f-BOC, ferf-butoxycarbonyl Bu, Butyl Bz, benzoyl CAN, ceric ammonium nitrate Cbz, benzyloxycarbonyl m-CPBA, m-chloroperoxybenzoic acid DAST, diethylaminosulfur trifluoride DBU, l,8-diazabicyclo[5.4.0]undec-7-ene DCC, /V. /V - d i eye I oh e x y I c ar bo -diimide DCM, dichloromethyl DCMME, dichloromethyl methyl ether DDQ, 2,3-dichloro-5,6-dicyano-l,4-benzoquinone DEAD, diethyl azodicarboxylate l-(+)-DET, L-(+)-diethyl tartrate l-DIPT, L-diisopropyl tartrate d-DIPT, D-diisopropyl tartrate DMAP, 4-dimethylaminopyridine DME, 1,2-dimethoxyethane DMF, /V./V-dimethylformamide DMP, 2,2-dimethoxypropane Et, ethyl Im, imidazole KHMDS, potassium hexamethyldisilazane Me, methyl Me2SO, dimethyl sulfoxide MOM, methoxymethyl MOMC1, methoxymethyl chloride Ms, methylsulfonyl MS, molecular sieves NBS, N-bromosuccinimide NIS, /V-iodosuccinimide NMO, /V-methylmorpho-line N-oxide PCC, pyridinium chlorochromate Ph, phenyl PMB, / -methoxvbenzyl PPTs, pyridiniump-toluenesulfonate i-Pr, isopropyl Py, pyridine rt, room temperature TBAF, tetrabutylammonium fluoride TBS, ferf-butyl dimethylsilyl TBDMSC1, f-butylchlorodimethylsilane Tf, trifhioromethylsulfonyl Tf20, trifluoromethylsulfonic anhydride TFA, trifluoroacetic acid THF, tetrahydrofuran TMS, trimethylsilyl TPAP, tetra-n-propylammonium perruthenate / -TsOH. / -toluenesulfonic acid... 

Ethylindole Indole, 3-ethyl- (8) 1H-lndole, 3-ethyl- (9) (1484-19-1) 3-Bromo-1-(tert-butyldimethylsilyl)indole 1H-Ind0le, 3-bromo-1-[(l, 1-dimethylethyl)-dimethylsilyl]- (13) (153942-69-9)... 

Highly diastereoselective 7-rro/o-radical cyclization of (bromomethyl)dimethylsilyl ethers 150, derived from ethyl y-hydroxy-a-methylenecarboxylates, bearing a bulky y-substituent such as isopropyl, cyclohexyl, and tert- mty in THF gave cyclic silyl ethers 151 bearing preferentially the ethoxycarbonyl group anti to the y-substituent (Equation 28) <2004TL4329>. 

A selection of ani a-metallocene derivatives in which two dimethylsilyl or ethyl-bridged Cp, indenyl or flnorenyl moieties encapsnlate the alkaline earth metal center have been prepared (see Fignre The structurally enforced... 

Chromatography.—Considerable attention is being paid to chromatographic methods for the separation and recognition of bile acids and their derivatives. The analysis (g.l.c.) of mixtures of bile acids and their conjugates is reported to be simplified by direct conversion into heptafluorobutyrate derivatives, which occurs with simultaneous deconjugation.The carboxyl function is apparently converted into its volatile mixed cholanyl-heptafluorobutyryl anhydride. Ethyl-dimethylsilyl ethers of bile acid ethyl esters are also reported to be suitable for... 

Kobayashi et al. have found that dimethyltrifloxysilyl enolates, prepared in situ from ketones and dimethylsilyl ditriflate in the presence of a tertiary amine, react smoothly with electrophiles such as aldehydes and acetals without catalyst at -78 °C to afford the corresponding aldol adducts in high yields [94]. The use of ethyl ketones as the substrates achieves high levels of syn selectivity (Scheme 10.29). 

An improved protocol for the efficient conversion of inosine into its 3 -phosphoramidite synthons for solid-phase oligonucleotide synthesis has been described. This procedure, which almost doubled the literature reported overall yields starting from inosine, was optimized for scale-up to multigram quantities. The portion-wise addition of DMT-Cl to a solution of inosine in DMSO and pyridine prevented multiple-site protections, which was also reported to occur in the presence of DMAP or triethylamine. Treatment with TBDMSCl in the presence of silver nitrate and pyridine in THF offered a mixture of the 2 - and 3 -substituted nucleosides from which the 5 -0-dimethoxytrityl-2 -0-tert-butyl-dimethylsilyl-protected inosine was crystallized in ethyl acetate. The mother liquor was enriched with the 2 -isomer by treatment with triethylamine in methanol. Standard conditions for phosphitylation were then applied to yield... 

Another analytical procedure for the extraction of degradation products of chemical munitions from water was developed by Sng and Ng. The technique is based on in situ derivatization by SPME. They investigated, for example, the derivatization of thiodiglycerol and ethyl-2-hydroxy ethyl sulfide. The derivatization reagent A-methyl-A-(tert-butyl-dimethylsilyl) trifiuoroacetamide with 1% fert-butyldimethylsilyl chloride, which forms hydrolytically stable ferf-butyldimethylsilyl derivatives, was used. Detection limits in the ppb range were realized with GC-MS in full scan mode. 

Bicchi, C., A. D. Amato, V. Manzin, A. Galli, and M. Galli, 1996. Gyclodextrin derivatives in gas chromatographic separation of racemic mixtures of volatile compounds. X. 2,3-di-0-ethyl-6-0-rerr-butyl-dimethylsilyl)- - and -Y-cyclodextrins. J. Chromatogr. A, 742 161-173. 

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