Gleason-type chiralauxiliaries were used for the synthesis of a novel class of sulfonium salts, obtained via methylation of the sulfide with Meerwein's salt. The salts were reacted with aldehydes under basic conditions to provide epoxy amides, which were reduced to their corresponding epoxy alcohols in excellent enantiomeric excesses. Interestingly, it was feasible to synthesize both enantiomeric
Organocatalytic asymmetric epoxidation reactions in water–alcohol solutions
作者:Wei Zhuang、Mauro Marigo、Karl Anker Jørgensen
DOI:10.1039/b512542a
日期:——
enantioselective organocatalytic epoxidation of alpha,beta-unsaturated aldehydes in aqueous solutions is presented. By the screening of the reaction conditions for the epoxidation of cinnamic aldehyde applying hydrogen peroxide as the oxidant and 2-[bis-(3,5-bis-trifluoromethyl-phenyl)-trimethylsilanyloxy-methyl]-pyrrolidine as the catalyst, a highly stereoselective reaction has been developed. The scope
The chemistry of spiroacetals. Enantiospecific synthesis of the spiroacetal units of avermectins B1b and B2b
作者:Raymond Baker、Christopher J. Swain、John C. Head
DOI:10.1039/c39850000309
日期:——
An enantiospecific synthesis of the spiroacetal sub-unit of avermectins B1b and B2b from the optically pure precursors acetylene(3) and lactone (4) is reported.
Deuterium incorporation experiments from (3<i>R</i>)- and (3<i>S</i>)-[3-2H]leucine into characteristic isoprenoidal lipid-core of halophilic archaea suggests the involvement of isovaleryl-CoA dehydrogenase
作者:Noriaki Yamauchi、Ryo Tanoue
DOI:10.1080/09168451.2017.1373588
日期:2017.11.2
incubation experiments with whole cell Halobacterium salinarum. Deuterium-labeled (3R)- and (3S)-[3-2H]leucine were freshly prepared as substrates from 2,3-epoxy-4-methyl-1-pentanol. Incorporation of deuteriumfrom (3S)-[3-2H]leucine and loss of deuteriumfrom (3R)-[3-2H]leucine in the lipid-core of H. salinarum was observed. Taken together with the results of our previous report, involving the incubation
Total Synthesis and Structural Confirmation of Chlorodysinosin A
作者:Stephen Hanessian、Juan R. Del Valle、Yafeng Xue、Niklas Blomberg
DOI:10.1021/ja0625834
日期:2006.8.1
The first enantiocontrolled total synthesis of the marine sponge metabolite chlorodysinosin A is described. The structure and absoluteconfiguration are identical to those of dysinosin A except for the presence of a novel 2S,3R-3-chloroleucine residue in the former. A concise stereocontrolled synthesis of the new chlorine-containing amino acid fragment was developed. An X-ray cocrystal structure of
描述了海洋海绵代谢物氯化肌球蛋白 A 的第一个对映体控制的全合成。除了在前者中存在新的 2S,3R-3-氯亮氨酸残基外,其结构和绝对构型与肌胞苷 A 相同。开发了新的含氯氨基酸片段的简洁立体控制合成。合成氯肌球蛋白 A 与凝血酶的 X 射线共晶结构证实了通过全合成实现的结构和构型分配。在天然产物铜绿素家族中,氯肌球蛋白 A 是丝氨酸蛋白酶凝血酶、凝血酶因子 VIIa 和因子 Xa 的最有效抑制剂,这些酶是导致人类血小板聚集和纤维蛋白网形成过程中的关键酶。