A concise and collective synthetic route to hypocretenolides was developed for the first time. This route features one-pot addition-alkylation and intramolecular 1,3-dipolar cycloaddition to efficiently assemble the 5/7/6 ring system. Our syntheses enabled multigram preparation of hypocretenolide which facilitated further biological evaluation.
View Article and Find Full Text PDFAlterbrassicicene D (1) and 3(11)-epoxyhypoestenone (2) were synthesised via a two-phase approach featuring concise construction of the 5-8-5 tricyclic intermediate and a tandem base-mediated epoxide opening-transannular oxa-Michael addition cascade to forge the complex skeleton of 2. The route is scalable and we generated 15 g of the tricyclic intermediate in 8 steps from (R)-limonene and 720 mg of the penultimate bioactive intermediate in a protecting-group-free manner. Our synthesis enabled the structural determination of 2 and provided materials for preliminary anticancer evaluation.
View Article and Find Full Text PDFA wavelength-tunable Q-switched erbium-doped fiber laser based on a digital micromirror device (DMD) is experimentally demonstrated. The Q-switched pulses are generated by incorporating a saturable absorption device made of graphene oxide. Stable Q-switched pulses at 1.
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