Ethyl moiety

Me Me X attach carbo OCH3 ed on end n of ethyl moiety Thenylchlor 96491-05-3 Rice... 

R is the spacer group which should also terminate in an anchor e.g. a mercaptan. He report here intermediate results in which R is the methyl and ethyl moiety the case of R=H is the subject of a separate paper (K. A. B. Lee, R. Mowry, G. McLennan and H. 0. Finklea, in press). Our primary concern is whether the bipyridiniums are incorporated into the mercaptan monolayer and whether they are located at a fixed distance relative to the gold surface. 

Alternatively, the use of an auxiliary with an (f )-stereochemistry at the phenyl-2-(phenylsulfanyl)ethyl moiety will lead to the formation of a 1,2-traro-glycoside because in this case the trans-decalin system will exert unfavourable steric interactions. The proposed mechanism has been supported by computational studies.39... 

FIGURE 10. Crystal structure of [PhCH NO 1.1 ( d I,( )111 . The H atoms of the phenyl ring and the ethyl moiety have been omitted the C atoms are only labeled by numbers197. Reproduced by permission of VCH, Weinheim... 

Li, et al. reported ethyl-bridged PMOs with Pd(ll) complexed to 3-aminopropyl-Itrimethoxysilane grafted onto the mesoporous walls to be an efficient catalysts for Barbier reaction of benzaldehyde and allyl bromide (Figure 16) [74]. Use of water as the reaction medium combined with the presence of ethyl moiety in the framework (which increased hydrophobicity of the pores) enhanced diffusion of the organic substrates. As can be seen in Table 3 the PMO material showed superior catalytic efficiency compared to grafted SBA-15 and MCM-41 materials with values comparable to homogeneous trials. 

Ethanol (ethyl alcohol, alcohol) is a simple organic molecule composed of a single hydroxyl group and a short two-carbon aliphatic chain, CH 3CH 2OH. The hydroxyl and ethyl moieties confer both hydrophilic and lipophilic properties on the molecule. Therefore, ethanol is an amphophile, a property important to its pharmacological activity. 

A new alcohol and phenol protective group, the l-[(2-trimethylsilyl)ethoxy]ethyl moiety, readily introduced using 2-(trimethylsilyl)ethyl vinyl ether and catalytic pyridinium p-toluenesulfonate (PPTS), has been described76. Cleavage is achieved under near-neutral conditions using TBAF monohydrate (equation 16). 

Similar octahedral facial silyl methyl hydride complexes of the type IrL3H(SiR3)Me have been shown to induce competitive C—H/Si—C reductive elimination depending on the electronic properties of the silyl ligand, thus affording a novel example of a metallation of silyl ligands or the metallation of the sp3C—H bond of the ethyl moiety when R = OEt. For the complex with R = Et, mixtures of different complexes are formed by the thermolysis with benzene (Scheme 32)198,199. 

FIGURE 3.34 Ethylbenzene in CDC13 at 600 MHz. The ethyl moiety is recognized by the CH3 triplet and the CH2 quartet. 

Later on, Schreiber used consecutively these two reactions in the key step for the synthesis of diterpene (-i-)-epoxydictimene (73), starting from natural (R)-pulegone [116,117]. This approach was built on their preliminary studies on Lewis acid mediated intermolecular Nicholas reactions [118]. They prepared functionalized enyne 70 bearing a mixed acetal. This compound was transformed into its dicobalt-hexacarbonyl complex and, in the presence of a carefully selected Lewis acid, it formed a stabilized carbocation by release of the more accessible ethyl moiety. This cation reacted intramolecularly with the allylsilane giving the central eight membered ring of the natural product... 

In the case of ethanol, however, the presumed intermediate is as hydrido-ethylene complex, which on reinsertion can give rise only to a single ethyl moiety. 

I Initial solvation of singlet species throught the ethyl moiety (a tew ps) I Coordination / spin-crossover to form an ethyl solvate (-100 ps)... 

Oxazolidine 130 is a masked aldimine bearing a chiral N-(2-hydroxy-l-phenyl)ethyl moiety and is readily available from (R)-phenylglycinol. Mannich reaction of 130 with Reformatsky reagent of ethyl bromodifluoroacetate produces difluorolactam 131 in high diastereoselectivity, which is then transformed to enantio-enriched (S)-3-amino-2,2-difluoro-3-phenylpropanoic acid 133 (see Scheme 9.28) [55]. 

Stereoselective synthesis of an a-alkylated ester has been carried out employing a polymer supported chiral oxazoline [13, 38]. An oxazoline bound ethyl moiety was alkylated with benzyl chloride to provide, after acid catalyzed detachment from the resin, an a-alkylated propionic acid ester in 43—48% yield and 56% ee. 

The third example to be discussed is -de-ethyl- -isopropionate ametryn (Product 11). FAB/(-)/MS analysis of the product showed the mass anions at m/z 228 (M-H)- and m/z 250 [(M"Na+)-H]-. FAB/(+)/MS analysis of this metabolite showed protonated mass ions at m/z 230 (M+H)+ and m/z 252 (M+Na)+. From the mass spectroscopic data, the molecular ion at m/z 229 was assigned for the metabolite, which is two mass units higher than the parent chemical and 28 mass units lower than Product 10 (last example), equating to a loss of the ethyl moiety from the molecule. Product 11 was, therefore, identified as -de-ethyl- -isopropionate ametryn. 

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