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[摘要]：Building upon the discovery of Suggs and Pires that N-(2-hydroxyethyl)glycine amides undergo rapid amide cleavage under mild conditions [Suggs, J. W.; Pires, R. M.Tetrahedron Lett.1997, , -2230], we synthesized the derivs. (4aa,8b,8aa)-1-ethylamido-8-hydroxydecahydroquinoline (4) and (4aa,8a,8ab)-1-ethylamido-8-hydroxydecahydroquinoline (5). These two species are conformationally constrained, but steric compression is not introduced between the hydroxyl group and the amide functionality it attacks. At 20 癈 and slightly basic pH, derivs. 4 and 5 undergo amide cleavage with half-lives of 21 min and 14 h, resp., which correspond to rate increases of 251- and 6.3-fold relative to the acyclic analog N-(2-hydroxyethyl)glycine amide (3). |
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