Ethyl cyclohexylideneaCETate

ETHYL CYCLOHEXYLIDENEACETATE (A1 -a-Cyclohexaneacetic acid, ethyl ester) 

Submitted by W. S. Wadsworth, Jr, and William D. Emmons 1 Checked by William E. Parham, R. M. Dodson, W. L. Salo, and J. N. Wemple 

500-ml., three-necked flask equipped with stirrer, thermometer, condenser, and dropping funnel is purged with dry nitrogen and charged with 16 g. (0.33 mole) of a 50% dispersion 

Sodium hydride, 50-51% in mineral oil, was supplied by Metal Hydrides Inc., Beverly, Massachusetts. 

Reagent grade benzene is filtered from sodium hydride just before use. 

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Ethyl 4-bromo-3-ketobutanoate, 46, 27 Ethyl 4-chloro-3-ketobutanoate, 46, 27 Ethyl cyclohexylideneacetate, 46, 44... 

This reaction is considered in Sections 5.2.3, p. 496, and 5.18.2, p. 799, and the specific examples that are included in this section are (i) the formation of ethyl cyclohexylideneacetate from cyclohexanone and triethyl phosphonoacetate in the solvent 1,2-dimethoxyethane and using sodium hydride as the base for the formation of the phosphoryl-stabilised anion 254 and (ii) the formation of ethyl (E)-but-2-enoate from acetaldehyde and triethyl phosphonoacetate under PTC conditions255 (Expt 5.215). In the latter example the (E configuration is to be expected from the general features of the reaction that are summarised in Section 5.2.3, p. 496. 

Reformatsky reaction/Peterson elimination sequence using highly activated Zn(Ag) -graphite preparation of ethyl cyclohexylideneacetate (Structure 14)... 

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