Disulfidebonds are a significant motif in life and drug-delivery systems. In particular, steric hindrance and stereoscopic disulfidelinkers are closely associated with the stability of antibody–drug conjugates, which affects the potency, selectivity, and pharmacokinetics of drugs. However, limited availability and diversity of tertiary thiols impede the construction of steric and stereoscopic disulfides
Etude de la reaction chlorocarbene-acetals de cetenes
作者:N. Slougui、G. Rousseau
DOI:10.1016/s0040-4020(01)96366-5
日期:1985.1
The reaction of chloro, chloromethyl and chlorophenyl carbenoids with ketene alkylsilylacetals has been studied. Excellent yields of cyclopropanation were observed and the unstable chlorocyclopropanone acetals formed were thermallyrearranged in high yield into α-substituted α,β-ethylenic esters. This new method for the synthesis of unsaturated esters appeared complementary of the known-ones.
Ketene alkyltrialkylsilyl acetals: synthesis, pyrolysis and NMR studies
作者:C. Ainsworth、Francis Chen、Yu-Neng Kuo
DOI:10.1016/s0022-328x(00)90475-3
日期:1972.12
are in agreement with fluxional behavior of compounds (III) in which the carbomethoxy and trimethylsilyloxy groups are cis. The results of mass fragmentation of ketene acetals (I) are similar to their thermolytic cleavage. Interestingly, however ketene-ketene acetals (II) in the mass spectrometer are fragmented into the ketene and ketene acetal fragments from which molecules they are thermally formed
已经开发了两种合成乙烯酮烷基三烷基甲硅烷基缩醛(I)的通用方法。第一种通过二取代的丙二酸酯与钠/二甲苯的反应,另一种方法是通过使取代的乙酸酯的α-阴离子与三甲基氯硅烷反应。还制备了碳甲氧基乙烯酮甲基三甲基甲硅烷基乙缩醛(III)。二芳基乙烯酮甲基三甲基甲硅烷基乙缩醛的热解以良好的收率得到二芳基乙烯酮。该反应的机理已被确立为分子内采用18 O.烷基,芳基和二烷基烯酮methyltrimethylsilyl缩醛热解,得到烯酮烯酮缩醛加成化合物(II)。芳基烯缩醛(I)的光谱研究与偶极结构Ar 2 C -- C +一致(OMe)OSiMe 3。得出的一般结论是,围绕碳bond碳双键的旋转自由度由连接的取代基决定。光谱研究与其中甲氧甲氧基和三甲基甲硅烷基氧基为顺式的化合物(III)的通量行为一致。乙烯酮缩醛(I)大量断裂的结果与它们的热裂解相似。有趣的是,质谱仪中的乙烯酮-乙烯酮缩醛(II)被分解
Metal reductions of malonates and oxalates. A covenient decarboxylation route for disubstituted malonates and synthesis of keten acetals
作者:Yu-Neng Kuo、Francis Chen、C. Ainsworth、Jordan J. Bloomfield
DOI:10.1039/c29710000136
日期:——
Alkali-metal reduction of disubstituted malonates or treatment of esters with base in the presence of trimethylchlorosilane gives high yields of the reactive disubstituted keten alkyl trimethylsilyl acetals, while diethyl oxalate, under similar conditions is reduced to 1,2-diethyl-1,2-bis(trimethylsilyloxy)ethylene.
Ketene O-alkyl O′-silyl acetals on reaction with nitric oxide or isomayl nitrite in the presence of titanium(IV) chloride provide either one of α-nitroso esters and oximes of α-keto esters.