Ethylchloro

The previous examples rehed on a radical termination. Cationic termination could also be used, after suitable oxidation of the final radical (Scheme 75) [211]. Thus, ester 252 was treated with base and ethylchloro-formate to give anion 253, which was oxidized to malonyl radical 254 by the ferrocenium ion. Cyclization/oxidation gave cation 256, which yielded 93% of malonate 257 by loss of the TMS group. This adduct was further elaborated upon and led to a cyclopentanoid monoterpene, dihydronepetal-actone. 

Acetylenic Grignard reagents react with carbon dioxide (CO2) to yield carboxylic acids of the type RC CCOOH. The reactions with ethylcarbonate [CO(OEt)2] or ethylchloro-... 

A simple method for the attachment of most reactants possessing free amino groups, i.e., oligopeptides and haptens (Weigand et al., 1981 Suter, 1982) is the pretreatment of polystyrene with GA (Barrett, 1977). Polystyrene is activated at a relatively low pH where GA has no strong tendency to react or to form polymers (Table 13.1). After the addition of the immunoreactant, the pH is raised to 8 or 9.5 with 100 mM carbonate (Dobbins Place and Schroeder, 1982), to increase the reactivity of GA. Either GA or ethylchloro-... 

In the same way alanyl-alanine and alanyl-alanine ester, which yielded caibethoxyl-alanyl-alanine ester when treated with ethylchloro-carbonate, can be obtained from alanine anhydride, and leucyl-leucine from leucine anhydride or leucinimide, which was first obtained in 1849 regarded as occurring in the protein molecule, by... 

EthyImereaptoacetate. Chloroacetylchloride (15 ml) was added to ethanol (100 ml). Potassium carbonate was added and the solution was stirred at room temperature for 1 hour. The potassium carbonate was filtered off. Excess ethanol was stripped on a rotary evaporator. The residue was added to 40 ml of toluene and the solution was washed with water. The toluene was stripped on an evaporator, yielding 15 ml of ethylchloro-acetate. 

I he ethylchloro compound produced in the first alkylation is moderately stable when pure but the diethyl Ti(lV) compound decomposes readily to give a Ti(IIl) compound and products derived from the ethyl radical. Olefin elimination from the ethyltitanium(III) complex presumably gives a hydride that can react further to give the observed dihydrido complex. 

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