Refernces
10.1016/j.tet.2010.01.059
The research aims to achieve a total synthesis of (t)-Z-deoxypukalide, a furanobutenolide-based cembranoid, using a combination of Stille and Nozaki–Hiyama–Kishi (NHK) coupling reactions as key steps. The study also developed a practical synthesis of the substituted butenolide intermediate 10 using a combination of ring-closing metathesis (RCM) and cross-metathesis (CM) reactions. The synthesis involved creating enantiomerically pure alkenyl iodides 10 and 11, which were then coupled with a stannylfuran intermediate to form alkenylfurans 28 and 29. However, intramolecular NHK reactions on these alkenylfurans resulted in low yields of the desired macrocyclic products. The researchers then successfully synthesized (t)-Z-deoxypukalide via a different route, starting from a furanmethanol derivative and using NHK conditions to form the macrocyclic homoallylic alcohol 37, which was then converted to the final product. The synthetic (t)-Z-deoxypukalide was confirmed to match the natural product in terms of spectroscopic data. The study concludes that while the intramolecular NHK reaction has limitations when an ester group is adjacent to the reacting aldehyde, alternative synthetic routes can achieve the desired natural product. Key chemicals used in the research include the starting materials such as cyclobutene ester 21, stannylfuran 27, and various reagents like Grubbs' catalyst, CrCl2, and tetrabutylammonium fluoride.
10.1016/j.mcat.2018.06.001
This study investigated the use of cerium or zinc oxides as promoters to improve the yield of furfuryl alcohol in the hydrogenation of furfural using an inexpensive copper-based catalyst supported on a mixed layer of cerolite/magnesium-montmorillonite. It was found that high copper loadings (15-30 wt.% copper) maintained high furfural conversions above 80 mol% after 5 h at 210 °C, while the addition of cerium oxide (CeO) or zinc oxide (ZnO) as promoters, while reducing furfural conversion, significantly improved the selectivity of furfuryl alcohol, reaching a maximum yield of above 80% after 5 h at 190 °C. The effects of copper content and the presence of promoters on the catalytic performance were also investigated, with the results indicating that moderate copper loadings favored the formation of 2-methylfuran, while higher loadings and the addition of cerium oxide (CeO) or zinc oxide (ZnO) improved the selectivity of furfuryl alcohol. The study concluded that the addition of CeO2 or ZnO changes the electron density of the active phase, thereby improving the selectivity of furfuryl alcohol and reducing the deactivation due to carbonaceous deposition.
10.1134/S1070427207100163
R. I. Khusnutdinov et al. explore the synthesis of levulinic acid esters and difurylmethane using furfuryl alcohol. The study investigates the reaction of furfuryl alcohol with aliphatic alcohols in a CCl4 system catalyzed by Fe(acac)3, achieving high yields of 80-98% for levulinic acid esters. The presence of HCl in the reaction mixture, formed from alcohols and CCl4 under the influence of iron compounds, is suggested to play a role in the catalysis. The authors also demonstrate the synthesis of 2,2'-difurylmethane in an 80% yield using Rh(PPh3)3Cl as a catalyst in a reaction with water and CCl4. The study provides a simpler and more accessible method for synthesizing these compounds compared to existing procedures, supported by spectral data confirming the structures of the synthesized compounds.
Xn
