Propargyl ketoximes

Azido derivatives of furazans have proved to be particularly useful for the synthesis of heterocyclic systems. Thus, by 1,3-dipolar addition of l-azido(4-amino-l,2,5-oxadiazol-3-yl)aldoxime 186 to propargyl alcohol and phenylacetyl-ene, bicyclic 4-amino-l,2,5-oxadiazol-3-yl(4-R-l,2,3-triazol-l-yl)ketoximes 187 were obtained (Equation 34) which in reaction with acetic anhydride afforded the corresponding 0-acyl derivatives <2003RJ0574>. 

Ketoxime ethers derived from structures (146)and (147) where R = H, methyl, propar-gyl, or C-alkyl-substituted propargyl showed Mg agonist activity in a rat aorta preparation, but no M2 agonist activity (185). 

It has been revealed that the reaction of ketoximes with propargylic ethers affords, instead of pyrroles or their predecessors 0-vinyl oximes, 0-(3-alkoxy-2- -propenyl) ketoximes (Scheme 1.127) [297]. 

SCHEME 1.127 Reaction of ketoximes with propargylic ethers in the KOH/DMSO system. 

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