Furans from allenones

Carbonyl compounds also react with allenes and, in fact, the first example of a gold-catalyzed addition of a nucleophile to allenes was the formation of furans from allenones. " The reaction was applied by Gevorgyan to the synthesis of substituted furans and in the case of bromide-substituted allenes halide migration was observed. Similar additions of... 

The present procedure evolved from our previous work on the conversion of allenals, allenones, and allenylcarbinols to furans and 2,5-dihydrofurans with catalytic silver nitrate (AgN03) in acetone.5-10 It has also been shown that allenylcarbinols can be converted to 2,5-dihydrofuran under these conditions.11 0- and y-Alkynyl allylic alcohols can also be isomerized to furans under strongly basic conditions with potassium tert-butoxide in tetrahydrofuran-tert-butyl alcohol-18-crown-6 or hexamethylphosphoramide (KO-t-Bu in THF-t-BuOH-18-crown-6 or HMPA).12 The AgNOa/silica gel method is milder, faster, and more efficient than the previously reported procedures.13 Moreover, it offers the potential advantage of catalyst recovery and possible applicability to a flow system in which a packed column, protected from light, could serve as the reactor.4... 

The present procedure evolved from our previous work on the conversion of allenals, allenones, and allenylcarbinols to furans and 2,5-dihydrofurans with catalytic silver nitrate (AgNOa) in acetone. It has also been shown that allenylcarbinols can... 

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