Selective acylations of multifunctional nucleophiles, including carbohydrates and nucleosides, with intermediates generated by Wolff rearrangement of amino acid derived diazo ketones: Preparation of beta-amino acid derivatives

The diazo ketones derived from Z- and Boc-protected alanine, valine, and alanyl-alanine (1-5) were decomposed by catalytic amounts of silver benzoate/Et(3)N in the presence of polyfunctional nucleophiles such as 3-methyl-1,3-butanediol, 2-aminoethanol, carbohydrates (xylofuranose and sucrose) and nucleosides (thymidine, adenosine derivatives). In many cases, products of beta-amino acylations are formed (6-14, 15b, 17-19, 21, 23, 24) with surprising functional group selectivities. The scope and limitations of the method are described.