Efficient One-Pot Synthesis of 2,2-Dimethyl-2H-chromenes via Pd(II)-Catalyzed Coupling and SiO2-Promoted Condensation of o-Halophenols with 2-Methyl-3-buten-2-ol
摘要:
An efficient synthesis of 2,2-dimethyl-2H-chromenes was accomplished by Pd(II)-catalyzed coupling and SiO2-promoted condensation of o-halophenols with 2-methyl-3-buten-2-ol (1,1-dimethylallyl alcohol) in one pot. The method is very general and can be useful for the synthesis of some natural 2,2-dimethyl-2H-chromenes.
Thermal cyclization of some m-acylaryl 1,1-dimethylpropargyl ethers (1a f) effected regioselective orthocyclization giving the corresponding 5-acyl-2,2-dimethyl-2H-chromenes (2a-f) (C) 2001 Elsevier Science Ltd. All rights reserved.