SYNTHESIS AND REACTIVITY OF METHYL γ-AZIDO BUTYRATES AND ETHYL δ-AZIDO VALERATES AND OF THE CORRESPONDING ACID CHLORIDES AS USEFUL REAGENTS FOR THE AMINOALKYLATION

Article abstract of DOI:10.1016/S0040-4020(01)81492-7

The azidoesters 13 and 14 and the corresponding acid chlorides 22 and 23 are shown to be interesting reagents for the nucleophilic and electrophilic aminoalkylation. α-substituted methyl γ-azidobutyrates 13 and ethyl δ-azido valerates 14 are easily accessible by alkylation of the lithium enolates of the parent compounds 13a and 14a respectively.Their chemoselective reduction leads to 3-substituted lactams 18 and 19.The acid chlorides 22 and 23 issued from 13 and 14 react with nucleophilic reagents, i.e. the carbanion of Meldrum acid, trimethylphosphite and n-butylmanganous iodide giving the the ω-azido,β-ketoesters 25 and 26, the ω-azido,α-acylphosphonates 29 and 30 and the ω-azido ketones 38 and 39 respectively in good yields.The treatment of 25 and 26 by Ph3P in anhydrous ether leads to the cyclic β-enaminoesters 27 and 28 whereas the α-acylphosphonates give the cyclic iminophosphonates 33 and 34a in good yields.These cyclizations occur via an intramolecular aza-Wittig reaction.