Synthesis and spectroscopic studies of furan-bridged polyazamacrocycles through 15,16-bis((prop-2-ynylamino)methyl)labdatriene transformations

Abstract: The design and the preparation of a small library of optically active polyazamacrocyclic compounds with a furan bridge, connected by (4-(methylaminomethyl)-1,2,3-triazole) rings with methylene, ethyloxyethyl or ethylethoxyethyl units from natural labdanoid lambertianic acid is reported. The synthesis of the key 15,16-bis((tert-butoxycarbonyl(prop-2-ynyl)amino)methyl)labda-8(9),13,15-labdatriene from the plant diterpenoid lambertianic acid is also described. CuAAC reaction of this compounds with various diazides in the presence of Cu(II)/sodium ascorbate in methylene chloride/water reaction medium led to the mentioned chiral macrocyclic compounds with a furan bridge binding Zn²⁺ ions in solution.