An efficient synthesis of 6H,7H-chromeno[4,3-b]chromenes and 6,7-dihydrothio chromeno[3,2-c]chromenes as 9-substituted xanthene like analogs

作者：Manna Sudipta Kumar; Parai Maloy Kumar; Panda Gautam^*

来源：Tetrahedron Letters, 2011, 52(45): 5951-5955.

DOI：10.1016/j.tetlet.2011.08.127

An efficient synthetic route with good overall yields to access 7-aryl/heteroaryl/alkyl substituted 6H,7H-chromeno[4,3-b]chromene, and 6,7-dihydrothiochromeno[3,2-c]chromene scaffolds has been developed. The route to these xanthene-like analogs involves a three-step reaction sequence: (1) Michael addition of readily available phenol and thiophenol to 4-chloro-2,2-dimethyl-2H-chromene-3-carbaldehyde, (2) Grignard reaction of different aryl, heteroaryl and alkyl magnesium bromides on the resulting carbaldehydes followed by (3) FeCl3 catalyzed spontaneous intramolecular Friedel-Craft's reaction on the diarylmethyl carbinols.

• 出版日期2011-11-9