Synthesis of 3-O-methylsericetin and related compounds

Abstract

3-O-Methylgalangin on reaction with prenyl bromide in the presence of methanolic methoxide gives 6,8-di-C-prenyl and 6-C-prenyl derivatives in 17% and 10% yields respectively; with 2-hydroxy-2-methylbut-3-ene it affords an 8-C-prenyl derivative besides the above two compounds. The above di-C-prenyl derivative on oxidative cyclization with DDQ yields a mixture of a linear pyran (3-O-methylsericetin) and an angular pyran (3-O-methylisosericetin).