Medium-sized Cyclophanes. Part 42.1 Synthesis of [2.n]Metacyclophan-1-ones and [2.n]Metacyclophane-1,2-diones

Abstract

Acetolysis of 10-endo,11-exo-dibromo-6,14-di-tert-bu tyl-9,17-dimethyl[3.2]metacyclophane cis-3b afforded the corresponding 10,11-diacetoxy derivative cis-5b with retention of configuration, whereas in the case of [4.2]metacyclophane cis-3c the same stereoselectivity was not observed: the diacetoxy derivatives 5 were converted into a 10,11-dione 10b and a 11,12-dione 10c via hydrolysis followed by Swern oxidation of dihydroxy derivatives 7b and 7c.