1: With N-iodo-succinimide; N-hexadecyl-N,N,N-trimethylammonium bromide; acetic acid in 1,4-dioxane; water T=20°C; 2: in 1,4-dioxane; water T=115°C; 0.25 h; Microwave irradiation; 3: With tert.-butylhydroperoxide; dipyridinium dichromate in 1,4-dioxane; water T=115°C; 0.25 h; Microwave irradiation;