The oxidative coupling of the readily available hepta-1, 6-diyn-4-01 (dipropargylcarbinol)(Ia) with oxygen in the presence of cuprous chloride and ammonium chloride has been studied. Acetylation followed by direct crystallization yielded a pure stereoisomer of the cyclic dimer 11, while chromatography gave a mixture of the two possible stereoisomers of 11, the cyclic trimer V and the cyclic tetramer VIII. Successive hydrogenation, saponification and ...
