Polyethylated triptycene derivatives.
The octaethyl triptycenes 7 and 8 were synthesized by Diels-Alder reaction of the octaethylanthracene 4with the corresponding benzynes. Low-temperature NMR spectra of 7 and 8 are consistent with the presence of the fully alternated conformation "a" of C(2) symmetry. However, in the determined crystal structures, the compounds adopt a higher energy conformation with a pair of vicinal ethyls oriented in the same direction.
Marks
Vered
V
Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900, Israel.
Nahmany
Moshe
M
Gottlieb
Hugo E
HE
Biali
Silvio E
SE