Hydro-azido-addition

Addition of Hydrazoic Acid Hydro-azido-addition... 

Trimethylsilyl halides can also be used for analogous reactions with arenediazo-nium tetrafluoroborates, as shown by Keumi et al. (1989). These authors treated 2-fluorenediazonium tetrafluoroborate in A/,Af-dimethylformamide or -acetamide with trimethylsilylchloride, -bromide, or -iodide in the presence of an excess of N-chlorosuccinimide, Af-bromosuccinimide, or methyl iodide, respectively, at 60 °C (Cl, Br) or at room temperature (I). The yields of the 2-halofluorenes were good in addition fluorene, the product of hydro-de-diazoniation, was obtained, if the reaction was run in tetrahydrofuran/Af,7V-dimethylformamide mixtures. The mechanism of these reactions, as well as that of the corresponding azido-de-diazoniation, is uncertain (see also Secs. 10.2 and 10.7). 

Ac) and gave a mixture of l,3,6-tri-0-acetyl-2,4-dideoxy-a-DL-//ireo, a- and P-DL-eo o-hexopyranoses (327-329) in the proportions 1 1.5 1. Basic reactions of racemic 2,4-dideoxyhexoses like glycosidation, substitution reactions at C-3 and C-6, and so on, were investigated. BFj-Catalyzed addition of benzyl carbamate to the double bond of 2-ethoxy-6-methanesulfonyloxymethyl-5,6-di-hydro-2H-pyran (279,R = Et,R = CH20S02Me) furnished a product which was directly converted with sodium azide into ethyl 6-azido-3-benzylcarbamido-... 

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