| 摘要 |
A method of cyclization of alpha , omega -diynes with a transition metal catalyst such as niobium or tantalum salts such as halogen to yield products such as dimers, trimers and higher polymers which may have benzocyclobutene groups, or none of these, depending on the size of n in the alpha , omega -diynes of the formula HC IDENTICAL C(CH2)nC IDENTICAL C-H. |
