O-Acylation of α-Diazo Ketones. A Novel Route to Alkenediazonium and 1,3-Dioxolium Salts

Article abstract of DOI:10.1021/jo00379a011

O-Acylation of α-diazo ketones with benzoyl triflate or diphenylacetyl triflate generates the corresponding β-(acyloxy)alkenediazonium salts 5 and 15.These thermolabile compounds can be trapped with isopropylamine at low temperature to give triazoles 21.Dediazoniation of 5 and 15 leads to 1,3-dioxolium salts 7 and 16 as well as small amounts of vinyl triflates 8 and 17 via intermediary vinyl cations.O-Benzoylation with benzoyl triflate has also been realized for the quinoid α-diazo ketone 9; the resulting diazonium salt 10 gives triazole 13 on treatment with isopropylamine.