The products of the Stevens 3,2-rearrangement of ammonium salts containing methyl and other (ethyl, propyl, butyl) alkyl groups along with 3-phenylprop-2-ynyl, under the reaction conditions undergo, roughly by half, intramolecular hydride shift with intermediate formation of immonium salts. The latter convert into enamino esters whose hydrolysis involving alkyl groups at the nitrogen atom gives rise to lower aliphatic aldehydes and the corresponding amino esters. Treatment with dilute hydrochloric acid of the reaction mixture containing enamino esters results in formation of hydrogenated and nonhydrogenated alkyl esters of a-keto acids. This mixture was reacted with concentrated hydrochloric acid to obtain 3-hydroxy-5-methyl-4-phenylfuran-2(5H)-one from the nonhydrogenated keto ester and to isolate pure the hydrogenated keto ester.
1,9-Bisammonium salts with a common 5-oxanona-2,7-diyn-1,9-ylene group and two allyl groups undergo Stevens 3,2-rearrangement under the action of a suspension of KOH in benzene to form branched acetylenic diamines.We found previously that ammonium salts containing 2-butynyl or 2-chloro-2-butenyl group as migrating fragments undergo Stevens 3,2-rearrangement under the action of bases to form products of the allene structure, which, in turn, undergo prototropic isomerization under the reaction conditions to form 1,4-diene products. The hydrolysis of these products with dilute HCl yielded the corresponding cyclopentenones, keto esters, and lactones [13 4]. Exclusive occurrence of the Stevens 3,2-rearrangement is also observed in ammonium salts containing simultaneously propargyl-and allyl-type groups [5].In this study we examined the Stevens rearrange-ÄÄÄÄÄÄÄÄÄÄÄÄ ment of ammonium salts Ia3Id containing a common 5-oxanona-2,7-diyn-1,9-ylene group as allyl accceptor. Salts Ia3Id were prepared by the scheme involving synthesis of di(2-propynyl) ether II [6] and diamine III by the Mannich reaction [7], followed by quaternization of 1,9-dimethylamino-5-oxanona-2,7-diyne III into salts Ia3Id with appropriate 2-alkenyl halide in ethanol (Table 1).The rearrangement of salts Ia3Id containing as 2-alkenyl substituents allyl, methallyl, 2-butenyl, and 3-phenyl-2-propenyl groups into amino ethers IVa3 IVd was effected by a suspension of KOH in benzene [5] ( Table 2).
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