Synthesis of 5,5,6,6,21,21,22,22-octamethyl-5,6,21,22-tetragerma[10.10]paracyclophane
摘要:
A [10,10]paracyclophane, 5,5,6,6,21,21,22,22-octamethyl-5,6,21,22-tetragerma[10.10]paracyclophane (4a), with two (RRGeGeRR2)-R-1-Ge-2-R-1- moieties in the center of two bridges, was prepared. An attempt to synthesize cyclophanes, 4b (R-1 = Me; R-2 = Ph) and 4c (R-1 = R-2 = Ph) was also made. The products were not analytically pure even after strenuous purification procedure to indicate that a double Wurtz coupling reaction is extremely difficult and necessarily accompanied by formation of polymeric byproducts. (C) 2003 Elsevier B.V. All rights reserved.