The Pummerer rearrangement reaction of 2- or 3-substituted 4-(phenylsulfinyl) butyricacids in the presence of an excess amount of acetic anhydride and a catalytic amount of p-toluenesulfonic acid in refluxing toluene for 1 h afforded 2- or 3-substituted 4-phenylthio-4-butanolide (17a–f). Thermolysis in pyridine of 4-phenylsulfinyl 4-butanolides, which were prepared by oxidation of 17a–f, afforded
Methods and compositions for determing a level of biologically active serum paraoxonase
申请人:Tawfik Dan S.
公开号:US20090305239A1
公开(公告)日:2009-12-10
A method of determining a level of biologically active PON enzyme is provided. The method comprising determining lactonase activity of the PON enzyme, the lactonase activity being indicative of the level of biologically active PON enzyme. Also provided are novel compounds which may be used for measuring a lactonase activity of an enzyme.
Pseudoesters and derivatives. Part 37. 1,3-Dipolar cycloaddition of diazo compounds to 2(5H)-furanones substituted at the 5-position by sulfur bearing groups
作者:Raquel Alguacil、Francisco Fariña、M Victoria Martín、M.Carmen Paredes
DOI:10.1016/s0040-4020(98)01028-x
日期:1999.1
The 1,3 dipolar cycloadditions of diazomethane and ethyldiazoacetate with differently substituted 5-sulfur-2(5H)-furanones (1–6) are reported. Cycloaddition of diazomethane occurs in a regio- and stereospecific manner to give the expected adducts 9–14, in good yield. The cycloaddition with ethyldiazoacetate occurs also in a regio- and stereospecific manner, but affords the corresponding 2-pyrazolines
Site-selective C(sp3)–H thiolation using thiosulfonates has been achieved using the decatungstate anion as a photocatalyst. Using the protocol, a variety of thiolated compounds were synthesized in good yields. The transformation consists of a cascade of double SH2 reactions, HAT and ArS group transfer, and PCET (proton-coupled electron transfer) of the leaving arylsulfonyl radical to arylsulfinic acid
使用十钨酸盐阴离子作为光催化剂,实现了使用硫代磺酸盐的位点选择性 C(sp 3 )–H 硫醇化。使用该方案,以良好的产率合成了多种硫醇化化合物。该转化由一系列双 S H 2 反应、HAT 和 ArS 基团转移以及离开芳基磺酰基到芳基亚磺酸的 PCET(质子耦合电子转移)组成,从而使催化剂 W 10 O 32 4−成为恢复了。