Syntheses of the cyclic tripeptides OF4949-III 1 and K-13 2 are reported, in which the key steps are intermolecular and intramolecular Negishi cross-coupling reactions, respectively. In addition, the synthesis of a protected isomer of K-13 25 is reported. The synthesis of K-13 features a tripeptidic organozinc reagent 11, one of the most highly functionalized such reagents to be described.
View Article and Find Full Text PDFBackground: Hepatocellular carcinoma (HCC) is a common malignancy worldwide and has a poor prognosis. Although surgery and liver transplantation provide better outcomes, most patients are not candidates due to advanced disease, lack of donor availability, or presence of comorbidities. Several percutaneous approaches such as transcatheter arterial chemoembolization (TACE) and percutaneous ethanol injection therapy (PEIT) have been developed for local control and can potentially increase survival in these patients.
View Article and Find Full Text PDFThe beta-hydroxysulfoxide moiety, after oxidation to sulfone, acts as a masked carbonyl group in a cyclic system, opening an easy access to differently substituted enantiomerically pure cyclic ketones by means of aluminium-mediated conjugate additions, stereoselective reductions and elimination by retrocondensation in basic medium.
View Article and Find Full Text PDFWildfires lead to important economic, social, and environmental losses, especially in areas of Mediterranean climate where they are of a high intensity and frequency. Over the past 30 years there has been a dramatic surge in the development and use of fire spread models. However, given the chaotic nature of environmental systems, it is very difficult to develop real-time fire-extinguishing models.
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