868856-34-2Relevant articles and documents
New approach for the construction of the coumarin frame and application in the total synthesis of natural products
Jerezano, Alberto,Jimenez, Fabiola,Del Carmen Cruz, Maria,Montiel, Luisa E.,Delgado, Francisco,Tamariz, Joaquin
experimental part, p. 185 - 198 (2011/04/17)
A new synthetic approach is described for building the coumarin scaffold through the Lewis acid-promoted cyclization of novel aryl 3-(dimethylamino)prop- 2-enoates 2a - 2f. The latter precursors were prepared via aminomethylenation of the corresponding aryl acetates 4a - 4f with the Bredereck reagent. This approach was used for the synthesis of biologically active natural compounds 1a - 1f, through a three-step procedure starting from the corresponding phenols.
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.
