A stereoselective total synthesis of 16-membered macrodiolide trichobotryside A has been accomplished. The key features are: regioselective epoxide opening, Reetz anti-allylation, Sharpless asymmetric epoxidation, cross metathesis and Yamaguchi protocols for esterification followed by macrolactonization.
An efficient protecting-group-free synthesis of tumonoic acid A and its derivatives has been accomplished. The synthesis started from commercially available n-octanal and employs the magnesium chloride catalysed anti-aldol reaction under the Evans protocol as the key step. Ethyl tumonoate A is a new tumonoic acid derivative with anti-inflammatory activity and inhibitory activity towards calcium oscillations in neocortical neurons.
A stereoselective total synthesis of 16-membered C 2 -symmetric macrodiolide Pyrenophorol, Tetrahydropyrenophorol and 4,4-diacetylpyrenophorol have been accomplished. The synthesis started from commercially available L-Aspartic acid and the key reactions involved are regioselective epoxide opening, CBS reduction, Pinnick oxidation and Mitsunobu dilactonization.
Experimental Section:General Information: All the air and moisture sensitive reactions were carried out under inert atmosphere (nitrogen or argon). Oven-dried glass apparatus were used to perform all the reactions. Freshly distilled anhydrous solvents were used for air and moisture sensitive reactions.Commercially available reagents were used as such. Purification of compounds was carried out via column chromatography by using silica gel (100-200 mesh) packed in glass columns. 1 H NMR and 13 C NMR were recorded in CDCl 3 an DMSO-d 6 solvents on 400 MHz and 500 MHz spectrometer respectively, using TMS as an internal standard. IR spectra were recorded on a Perkin-Elmer FT-IR 240-c spectro photometer using KBr / Thin Film optics. Mass spectra were recorded on a Finnigan MAT 1020 mass spectrometer operating at 70 eV. Optical rotation values were recorded on Horiba sepa 300 polarimeter using a 2 mL cell with a 10 mm path length. High resolution mass spectra (HRMS) [ESI+] were obtained using either a TOF or a double focusing spectrometer.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.