Medium-sized cyclophanes. Part XVIII. Iodine-induced cycloisomerization of methyl-, ethyl-, and isopropyl-[2.2]metacyclophanes. π-Basicity and additional strain energy terms as controlling factors
作者:Takeo Sato、Tetsuo Takemura
DOI:10.1039/p29760001195
日期:——
Methyl-, ethyl-, and isopropyl-[2.2]metacyclophanes (4)–(14), in which up to eight alkyl groups are present, have been prepared. The relative rates of iodine-induced cycloisomerization were determined by competitive experiments and gave the order of reactivity as (12) > (9)≃(10) > (11) > (5) > (8) > (4) > (3). The presence of alkyl groups adjacent to the bridging methylene enhanced the rate. For the