Creation of New Medicines Based on the Characteristic Reactivity of Allenes

丙二烯氨基甲酸酯（1，4-亚乙烯基-2-恶唑烷酮）的丙二烯键表现出变色反应性，其反应模式随反应物种类的不同而变化。与末端烯烃和炔，1以协同方式进行[2+2]环加成，并提供亚甲基环丁烷和亚甲基环丁烯。产量都很好。环加成反应在严格的热活化条件（70-100 ℃）下进行，并保持烯烃双键的构型。通常，[2+2]环加成反应是一个热禁戒过程，1的独特反应性可以用[2π+2π+2π] Huckel过渡态来解释。与烯醇和烯丙基硅烷，1经历了独特的1，3-磺酰基迁移，然后通过反电子需求狄尔斯-阿尔德反应产生四氢吡啶衍生物。与硅烷（RnSiH 4-n，n = 1-3）、醇和硫醇一起，1经历1，3-磺酰基迁移并以优异的产率提供各种4-亚丙基-2-恶唑烷酮。

The allene bond of allene carbamate (1, 4-vinylidene-2-oxazolidinone) shows a chameleonic reactivity, changing the reaction patters widely depending on the kinds of its reaction partners. With terminal alkenes and alkynes, 1 undergoes [2+2]cycloaddition in a concerted manner and provides methylene cyclobutanes and methylenecyclobutenes. Respectively in good yields. The cycloaddition proceeds under strictly thermal activation conditions (70-100 ℃) with retention of the configuration of the alkene double bonds. Usually, [2+2]cycloaddition is a thermally forbidden process and the unique reactivity of 1 is explained on the basis of a [2π+2π+2π] Huckel transition state. With enols and allylsilanes, 1 undergoes unique 1,3-sulfonyl migration followed by the inverse electron demand Diels-Alder reaction giving rise to tetrehydropyridine derivatives. With silanes (RnSiH4-n, n = 1-3), alcohols, and thiols, 1 undergoes the 1,3-sulfonyl migration and provides a variety of 4-propylidene-2- oxazolidinones in excellent yields.