The 6-methoxy and 6-tetrahydropyranyloxy-2,3-dihydro-1,4-benzodioxins can be lithiated at the 5-position to give intermediate lithio derivatives which react with various electrophiles to afford, after hydrolysis, 5-substituted-6-methoxy and 6-hydroxy-2,3-dihydro-1,4-benzodioxins.
GUILLAUMET, G.;HRETANI, M.;COUDERT, G., TETRAHEDRON LETT., 29,(1988) N 4, 475-476