Rupe reaction

Z)-butylteUurobutenines, upon treatment with boiling 85% formic acid (Rupe reaction conditions), do not form the expected a,/ -unsaturated ketones, bnt are converted into snbstitnted tellnrophenes. ... 

Acetaldoxime was converted to acetonitrile in about 80% yield over an H-ZSM-5 catalyst at 300°C (Eqn. 22.23).5 Heating aldoximes with montmorillonite KSF in refluxing toluene gave the nitriles in 65-85% yields. Rupe Reaction... 

The acid catalyzed rearrangement of tertiary acetylenic alcohols, the Rupe reaction, is a viable procedure for the preparation of a,p-unsaturated carbonyl compounds. Under standard acidic conditions, however, the products can polymerize and various by-products can be produced. With solid acids these problems are minimized. The reaction of an acetylenic tertiary alcohol with Nafion-H gave the a,P-unsaturated ketone in good to very good yields (Eqns. 22.24—25). When this reaction was run using a vanadium pillared... 

Rupe reaction. The dehydration of an acetylenic alcohol to a substituted vinyl acetylene followed... 

Rupe reaction. Rupe reaction converts alkynyl tertiary alcohols to a,S unsaturated carbonyl compounds (17). Table IV summarizes the utility of NAFION. Yields are based upon Isolated product and vary from 60 to 88%. This method suppresses the normal by-product formation from the polymerization of a,3 unsaturated compounds, giving considerable synthetic advantage. 

Conversely, Bestmann and coworkers utilized the Rupe reaction to prepare normanicone , a mandibular gland pheromone in the North American ant species manica mutica and manica bradley. In a manner similar to above, acetylide addition produced alcohol 44 which was treated with P2O5 to yield the Rupe product 45, albeit in low yield. 

The utility of the Rupe reaction has been impressively demonstrated in its large scale pilot plant implementation for the synthesis of steroid intermediate 58. Using the strongly acidic Amberlyst type resin A-252 in ethyl acetate, the reaction proceeded to produce 58 from 57 in 78% yield and 98% purity. Notably, the reaction has been accomplished on 64 kg scale, in a manner more inexpensive and environmentally benign than previously described. ... 

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