A cyclisation of 1‐bromo‐5,5,10,10‐tetraethoxycarbonyl‐2,7‐decadiyne (9b) using NaH in dilute solution gives 1,1,6,6‐tetraethoxycarbonyl‐cyclodeca‐3,8‐diyne (8) in 17,6% yield. 9b is prepared by condensation of 1,1,6,6‐tetraethoxycarbonyl‐3‐hexyne with 1,4‐dibromo‐2‐butyne.