685144-65-4Relevant academic research and scientific papers
An efficient synthesis of benzofurans and their application in the preparation of natural products of the genus Calea
Del Carmen Cruz, María,Tamariz, Joaquín
, p. 10061 - 10072 (2007/10/03)
The intramolecular cyclization of the β-substituted olefins methyl 2-aryloxy-3-dimethylaminopropenoates 3a-3f catalyzed by Lewis acids leads to a short and novel synthesis of benzofurans 2a-2f. When the olefins 4-dimethylamino-3-aryloxy-3-buten-2-ones 4a-4f were used, the cyclization process was faster and provided the corresponding substituted 2-acetylbenzofurans 1a-1f. Among the latter, naturally occurring compounds calebertin (1a), caleprunin A (1b), and caleprunin B (1c) were prepared in good overall yields. These benzofurans were also obtained by direct treatment under MW irradiation of the precursors 1-aryloxypropan-2-ones 7a-7c with DMFDMA, followed by addition of the catalyst, resulting in a route that was one step shorter.
Captodative olefins: Methyl 2-aryloxy-3-dimethyl-aminopropenoates and their application in a new synthesis of benzofurans
Cruz, María Del Carmen,Tamariz, Joaquín
, p. 2377 - 2380 (2007/10/03)
The β-substituted captodative olefins methyl 2-aryloxy-3- dimethylaminopropenoates 4a-h were synthesized, via aminomethylenation of the corresponding 2-phenoxyacetic esters 9a-h. Lewis acid promoted intramolecular cyclization of alkenes 4 led to benzofurans 7a-h, in an efficient synthetic approach to the benzofuran frame.
