Synthesis and Structure of Functionalized Cyclododecadiynes and ‐dienes

Abstract
The cyclododecadiynes 3b–d, 8b–d, and 10b–c with functionalities in two propargylic positions, as well as the monofunctionalized diyne 13b have been prepared from simple open‐chain building blocks. In the DMPU ( = N,N'‐dimethylpropyleneurea)‐assisted ring‐closing alkylation of 1,7‐diynes, the twelve‐membered ring compounds have been prepared in yields of 16–55%. The preparation of the diene‐diyne 15 and the cyclododeca‐5,11‐diyne‐1,4‐dione 18 are described.