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چکیده
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Multicomponent 1,3-Dipolar cycloaddition reactions pave a way for the stereoselective synthesis of many spiroheterocycles through the cycloaddition reaction of nonstabilized azomethine ylides with the olefinic dipolarophiles. Substituted indolizidines have attracted much interest as they contribute the central structural element of many alkaloids and pharmacological active compounds [1]. Althogh amino acids have been used extensively in synthesis for a wide variety of heterocyclic compound but there seems to be no report in which available pipecolinic acid has been used to synthesis of valuable substituted indolizidines,Due to the above mentioned reasons and as a part of our ongoing research program on the synthesis of these kinds of spiro heterocycles [2], we have developed a synthetic route for producing a new class of spiro indolizidines 1, for the first time in good yeilds, through the 1,3-Dipolar cycloaddition reaction of chalcones, which are common substructures in numerous natural products, with nonstabilized azomethine ylides generated by decarboxylative condensation reaction of acenaphthenequinon with pipecolinic acid. The reactions were carried out under classical, solvent free and ultrasonic irradiation conditions in a single pot. The best reaction was carried out in methanol as solvent. The structure of products were confirmcd by spectroscopic methods.
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