An Efficient Method to Construct 2-vinylidenyl Cyclobutanone Derivatives and its Structural Determination
摘要:
2-Vinylidenyl cyclobutanone derivatives 5 can be readily synthesized from the dialkynyl cyclopropanols 4 through a consecutive process of 1,6-diynes carbocyclization and ring enlargement of cyclopropnaol unit by using AuCl(PPh3)/AgPF6 as catalyst in DCE at rt. The structure of compound 5a was identified to a 2-vinylidenyl cyclobutanone by X-ray crystallographic analysis. The unit cell has monoclinic P2(1)/c symmetry with the cell parameters a = 10.919(2) angstrom, b = 17.508(4) angstrom, c = 7.9219(16) angstrom, and Z = 4.