Ketene, diethyl ketal

Ketene diethylacetal, 23, 43 Ketene, diethyl ketal, 23, 43 Ketene dimer, 21, 4, 64 Ketene lamp, 21, 65 Keto acid, 20, 2... 

Ketene diethyl ketals. These useful intermediates can be obtained by a Wittig-Homer reaction of the anion of 1 with aldehydes and ketones. Higher yields are obtained when the adducts are isolated and then treated with potassium f-butoxide.2... 

Kerosene, purified, 24, 7 Ketene, 21, 13, 64 Ketene diethylacetal, 23, 45 Ketene, diethyl ketal, 23, 45 Ketene dimer, 21, 4, 64 Ketene lamp, 21, 65 Keto acid, 20, 2 -Ketoglutaric acid, 26, 42 Ketone, 2-Fluorenyl methyl, 28,3,63 Ketone, methyl 9-phenanthryl, 28,6 Ketone, methyl 2-thienyl, 28,1 Knoevenagel condensation, 23, 60 24, 92 25, 42, 51 27, 24 28, 24 Kolbc synthesis of an alkyl a,a>-dicar-boxylatc, 21, 48... 

Truce and Norrell noticed in 1963 that sulfenes readily undergo 2 - - 2 cycloaddition to ketene diethyl acetal with the formation of 3,3-diethoxythie-tane 1,1-dioxides. The same reaction was carried out by Paquette, using 1,1-dioxide ketals with cyclic a-halo sulfones in which the corresponding chloroketal derivatives 47 were formed. This approach may be illustrated by the addition of ketene diethyl acetal to halogenated sulfenes and to... 

Treatment of diethyl ketals of 3-thietanone 1,1-dioxide with bases (NaOH, phenyllithium" ) results in the elimination of ethanol to give 3-ethoxythiete 1,1-dioxides, for example, 257. 3-Methoxy-2H-thiete 1,1-dioxide is obtained by elimination of methoxytrimethylsilane from the ketal of 2-trimethylsilyl-3-thietanone 1,1-dioxide. The cycloaddition of ketene yy.,4i7,494b.495a,s93,6oo. 49sa,60i sulfenes derived from... 

Readily available methylthiomaleic anhydride reacts smoothly with dienes giving Diels-Alder adducts [e.g. (149) from 2-methyl-buta-1,3-diene] which are transformed to j8-keto-ester ketals, e.g. (150), by oxidative decarboxylation (cf. ref. 49). Intermediate (149) can also be converted into the corresponding a-methylene-ketone or oxidized to salicylic esters. a-Nitroacetoacetates (151) have been prepared by condensing a-nitroacetates with ketene diethyl acetal followed by hydrolysis of the acetoacetate enol ether thus formed. 

P-lactams Aceto(carbonyl)cyclopenta-dienyl-(triphenylphosphine)iron. Benzene-sulfenyl chloride. Chlorodicarbonylrho-dium(I) dimer. 2-Chloro-l-methylpyridin-ium iodide. Dimethylformamide-Thionyl chloride. Ketene bis(trimethylsilyl)-ketals.p-Tolylsulfinylacetic acid. Triphenyl-phosphine-Diethyl azodicarboxylate. Zinc. 

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