Ethoxy-1-butyne

Since 1-ethoxy-1-butyne is very volatile, extreme care should be taken during the work-up to minimize loss of product due to evaporation. Extractions especially should be accompanied by careful and frequent venting of the separatory funnel to prevent excessive pressure. 

Some studies seeking preferred conditions for this reaction have been reported. Optimum yields of 1-ethoxy-1-propyne and 1-ethoxy-l-butyne are found when the product is worked up before allowing the ammonia solvent to evaporate, as the product evidently volatilizes with the ammonia. An experiment with 1-ethoxy-1-propyne showed a marked increase in yield when ammonia predried over calcium hydride was used instead of ammonia directly from the cylinder. A twofold excess of ethyl bromide is required to obtain a good yield of l-ethoxy-l-but5me, since elimination apparently competes with alkylation in this case. 

See 4-Ethoxy-2-methyl-3-butyn-2-ol See other ACETYLENIC COMPOUNDS... 

Whereas Fischer-type chromium carbenes react with alkenes, dienes, and alkynes to afford cyclopropanes, vinylcyclopropanes, and aromatic compounds, the iron Fischer-type carbene (47, e.g. R = Ph) reacts with alkenes and dienes to afford primarily coupled products (58) and (59) (Scheme 21). The mechanism proposed involves a [2 -F 2] cycloaddition of the alkene the carbene to form a metallacyclobutane see Metallacycle) (60). This intermediate undergoes jS-hydride elimination followed by reductive elimination to generate the coupled products. Carbenes (47) also react with alkynes under CO pressure (ca. 3.7 atm) to afford 6-ethoxy-o -pyrone complexes (61). The unstable metallacyclobutene (62) is produced by the reaction of (47) with 2-butyne in the absence of CO. Complex (62) decomposes to the pyrone complex (61). It has been suggested that the intermediate (62) is transformed into the vinylketene complex... 

SAFETY PROFILE A poison by intravenous route. Moderately toxic by ingestion, intraperitoneal, and subcutaneous routes. Human systemic effects heart changes, cyanosis, flaccid paralysis with appropriate anesthesia. An experimental teratogen. Mutadon data reported. Potentially explosive reaction when heated with ethoxyethynyl alcohols (e.g., 1-ethoxy-3-methyl-l-butyn-3-ol). When heated to decomposition it emits toxic fumes of SOx. See also SULFATES. 

C7H1202 4-ethoxy-2-methyl-3-butyn-2-ol 2041-76-1 447.69 38.882 2 11587 C7H13CI cis-1-chloro-1-heptene 53268-66-9 423.15 36.959 1.2... 

Ethoxy-2-methyl-3-butyn-2-ol, 2844 Ethylene oxide, Contaminants, 0829 Ethyl oxalyl chloride, 1456 Hydrogen peroxide, Coal, 4477 Hydrogen peroxide, Copper(ll) chloride, 4477... 

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