730-46-1Relevant articles and documents
W(OTf)6-Catalyzed Synthesis of Γ-Lactones by Ring Contraction of Macrolides or Ring Closing of Terminal Hydroxyfatty Acids in Ionic Liquid
Xie, Zhong-Yu,Deng, Jin,Fu, Yao
, p. 2332 - 2339 (2018/07/31)
γ-Lactones are an important class of fine chemical products and are widely used in perfumes, medicines, pesticides, dyes, and other fields. Herein, a new method for γ-lactones preparation based on ring contraction was developed. Starting from macrolides, W(OTf)6 was used to catalyze the ring-opening polymerization then depolymerization. The depolymerization step was not a common ring-closing process, and the carbon number of the ring was reduced one by one by rearrangement to form the most thermodynamically stable five-membered ring compounds. γ-Caprolactone (180 °C for 10 h) was obtained in a yield of 94 % when [EMIM]OTf was used as the solvent, and the yield of isolated product was up to 85 %. The interaction of various components and the reaction mechanism were studied by FTIR spectroscopy and 1H NMR spectroscopy, respectively. Furthermore, γ-lactones could be produced when the substrate was extended to terminal hydroxyfatty acids. Unexpectedly, the catalyst was poisoned by 1 equivalent of H2O added during the process and thus the yield decreased greatly. The reaction is green and simple, and proceeds in one pot with high atom economy (100 % for macrolides and with water as the only byproduct for terminal hydroxyfatty acid), which provides a promising approach to synthesizing γ-lactones.
Sensory-directed identification of creaminess-enhancing volatiles and semivolatiles in full-fat cream
Schlutt, Birgit,Moran, Noelia,Schieberle, Peter,Hofmann, Thomas
, p. 9634 - 9645 (2008/03/17)
Aimed at defining the chemical nature of creaminess-related flavor compounds in dairy products on a molecular level, a full-fat cream was analyzed for sensorially active volatiles and semivolatiles by means of activity-guided screening techniques. Application of the aroma extract dilution analysis on an aroma distillate prepared from pasteurized cream (30% fat) revealed δ-decalactone, (Z)-6-dodeceno-γ-lactone, γ-dodecalactone, δ-dodecalactone, and 3-methylindole with by far the highest flavor dilution (FD) factors among the 34 odor-active volatiles identified. Using a complementary approach involving silica column chromatography and fractionated high-vacuum distillation combined with sensory experiments enabled the additional identification of δ-tetradecalactone, δ-hexadecalactone, γ-tetradecalactone, γ-hexadecalactone, and δ-octadecalactone as semivolatile flavor components in the cream fat. Although a series of lactones is present in dairy cream, spiking of cream samples with individual lactones revealed that only the δ-tetradecalactone is able to enhance the typical retronasal creamy flavor of the product when added in amounts above its theshold level of 66 μmol/kg. Rather than contributing to the retronasal aroma of cream, first evidence was found that, particularly, γ- and δ-octadecalactones and γ- and δ-eicosalactones are able to influence the melting behavior of cream in the oral cavity.
