Stereoselective synthesis of resorcylic acid lactone Cochliomycin B

Enantioselective Total Synthesis of the Neurotoxin Caramboxin

“…Although this product is commercially available, its excessive price led us to synthesize 6 in two steps from cheap and commercially available ethyl acetoacetate 7 . Accordingly, ethyl acetoacetate was converted to ethyl orsellinate 8 by an intramolecular condensation using the sequential addition of sodium hydride and n -butyllithium in dry THF (modification of Barrett’s protocol) − in 34% yield (Scheme ). Next, saponification by an aqueous solution of sodium hydroxide under reflux conditions gave orsellinic acid 6 in good 86% yield.…”

“…Next, saponification by an aqueous solution of sodium hydroxide under reflux conditions gave orsellinic acid 6 in good 86% yield. The resorcylate derivative 9 was next synthesized by the reaction of orsellinic acid 6 with acetone under the action of thionyl chloride in 1,2-dimethoxyethane in quantitative yield (Scheme ) ,− followed by O -methylation of phenol 9 with methyl iodide in the presence of potassium carbonate giving the methyl ether 10 in 94% yield.…”

“…The last step consisted of the benzylic bromination of compound 10 . The classical Wohl–Ziegler conditions [NBS ( N -bromosuccinimide) and a catalytic amount of AIBN (azobis­(isobutyronitrile)) in CCl 4 ] afforded the desired benzyl bromide derivative 4 in 69% yield. ,, Since CCl 4 is no longer available from suppliers, we tried to replace CCl 4 with another solvent, but this reaction is ineffective in dichloromethane, 1,2-dichlorobenzene, or acetonitrile. We thus evaluated alternative and eco-friendly conditions to prepare compound 4 (see the optimization table in the SI).…”

Protecting group-free synthesis of the fungicide Mandipropamid

“…As part of our regular research program in synthesis of biologically active molecules, herein we report a simple and protecting group free synthesis of mandipropamid. [14][15][16][17][18]…”

Stereoselective total synthesis of dodoneine

“…[2][3][4][5][6] The interesting pharmacological properties motivated synthetic chemists and lead to its synthesis in various pathways. [7][8][9][10][11][12][13][14][15] As passion of our research, the synthesis of biologically active natural molecules, [16][17][18][19][20][21] herein we report, the stereoselective total synthesis of (+)-Dodoneine by adopting Sharpless asymmetric epoxidation methodology, 1,3-syndiastereoselective reduction and Horner-Wadsworth-Emmons olefination reactions as key steps.…”