The First Crystal Structure Analysis of Cyclododeca-2,8-diyne-1,10-diols
摘要:
Cyclododeca-2,8-diyne-1,10-diol, (6), C12H16O2, and 1,10-dimethylcyclododeca-2,8-diyne-1,10-diol, (11), C14H20O2, have been prepared and their structures determined. Both crystallize in centrosymmetric space groups and the molecules have approximate C-2 symmetry. For compound (6), the lengths of the triple bonds are 1.184(3) (C2=C3) and 1.189(3) Angstrom (C8=C9). The bond angles at the triple bonds (C1-C2=C3 and C8=C9-C-10) deviate by less than 6 degrees from 180 degrees. For compound (11), the lengths of the triple bonds are 1.190(3) (C2=C3) and 1.188(3) Angstrom (C8=C9), and the bond angles at the triple bonds are close to 175.5 degrees. In both compounds, the two 3-hexyne chains maintain a 'crossed' arrangement whereas the two alkylene chains are arranged in a manner similar to that described for unsubstituted cyclododecane.
Synthesis and Structure of Functionalized Cyclododecadiynes and -dienes
作者:Christoph Boss、Reinhart Keese
DOI:10.1002/hlca.19960790811
日期:1996.12.11
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