The synthesis of the 10-, 11-, 13-, 14- and 16-membered cycloalkadiynes 3a-b, 4a-b, 6a-b, 7a-b, 10a-b and 11a-b containing functional groups either in two propargylic or two homopropargylic positions is described. The key step of the synthetic scheme is the DMPU assisted double alkylation of two terminal alkyne units leading to the carbocycles mentioned above in moderate to good yield via a three step pathway. (C) 1997 Elsevier Science Ltd.