A facile synthesis of 5,5-dideutero-4-dimethyl(phenyl)silyl-6-undecyl-tetrahydropyran-2-one as a deuterium labeled synthon for (−)-tetrahydrolipstatin and (+)-δ-hexadecanolide
作者:Sandip J. Wagh、Raghunath Chowdhury、Sulekha Mukhopadhyay、Sunil K. Ghosh
DOI:10.1002/jlcr.3081
日期:2013.11
Deuterium-labeled biologically active compounds are gaining importance because they can be utilized as tracers or surrogate compounds to understand the mechanism of action, absorption, distribution, metabolism, and excretion. Deuterated drug molecules (heavy drugs) become novel as well as popular because of better stability and bioavailability compared with their hydrogen analogs. Labeling of organic molecules with deuterium at specific positions is thus gaining popularity. In this work, we have exploited a highly regioselective and enantioselective direct Michael addition of methyl-d3 alkyl ketones to dimethyl(phenyl)silylmethylene malonate that was catalyzed by (S)-N-(2-pyrrolidinylmethyl)pyrrolidine/trifluoroacetic acid/ D2O combination with high yield and isotopic purity. The 5,5-dideutero-4-dimethyl(phenyl)silyl-6-undecyl-tetrahydropyran-2-one was obtained from the adduct of methyl-d3 undecanyl ketone and dimethyl(phenyl)silylmethylene malonate by a silicon controlled diastereoselective ketone reduction, lactonization, and deethoxycarbonylation. The dideuterated silylated tetrahydropyran-2-one is the precursor for geminal 2H2-labeled (+)-4-hydroxy-6-undecyl-tetrahydropyran-2-one, an advanced intermediate for gem-dideutero (–)-tetrahydrolipstatin and (+)-δ-hexadecanolide syntheses.
氘标记的生物活性化合物正变得越来越重要,因为它们可以作为示踪剂或替代化合物,用于理解作用机制、吸收、分布、代谢和排泄。因此,氘化药物分子(重药物)因其相比氢的类似物具有更好的稳定性和生物可利用性而成为新颖且受欢迎的选择。因此,在特定位置用氘标记有机分子也越来越受欢迎。在本研究中,我们利用了一种高区域选择性和对映选择性的直接迈克尔加成反应,将甲基-d3烷基酮与二甲基(苯基)硅亚甲基马来酸酯进行结合,该反应由(S)-N-(2-吡咯烷基甲基)吡咯烷/p-三氟乙酸/D2O组合催化,得到了高产率和同位素纯度。由甲基-d3十一烷基酮和二甲基(苯基)硅亚甲基马来酸酯的加合物,通过硅控制的二对映体选择性酮还原、内酯化和去醇羧基化反应,获得了5,5-二氘-4-二甲基(苯基)硅基-6-十一烷基-四氢吡喃-2-酮。该二氘化的硅化四氢吡喃-2-酮是双氘标记(+)-4-羟基-6-十一烷基-四氢吡喃-2-酮的前体,这是合成双氘化(–)-四氢脂肪酶抑制剂和(+)-δ-十六烷内酯的先进中间体。