The preliminary results of a study on the stereocontrolled racemic synthesis of thaxtomins A and B are disclosed. The synthesis features a new C-C bond-forming reaction: dilithium tetrachlorocuprate was shown to be an efficient catalyst for cross-coupling reactions of lithiated 1,4-dialkyl-2,5-piperazinedione anions with gramine methosulfate and alkyl halides.
Synthèse d'analogues structuraux de thaxtomines, phytotoxines responsables de la gale de la pomme de terre
Cross coupling reactions of lithiated 2,5-piperazinedione anions with gramine methosulfate and alkylhalides were shown to be catalyzed by copper reagents, e.g. dilithium tetrachlorocuprate and copper (I) iodide. Based on this findings, the results of the first method for preparation of racemic thaxtomins are reported. Compound 1c, chosen as a synthetic model, was prepared in five steps in 19% overall