Versatile intermediates for heteroatom-substituted adamantane derivatives

Abstract

22)Opening at the less substituted carbon has been called the "normal" mode while opening at the more substituted carbon has been called the "abnormal" mode (cf. ref 18-20). Since this terminology is backwards for carbocation reactions, its use here would be confusing. We recommend that such terminology not be perpetuated. 9-Acetoxybicyclo[3.3.l]nona-2,6(7)-diene (18), a versatile intermediate for t h e synthesis o f heteroatom substituted adamantanes, was prepared in eight steps f r o m the commercially available 1,4-cyclohexanediol. T h i s intermediate m a y be used in t h e synthesis o f substituted oxa-, aza-, a n d thiaadamantanes. Utility o f this intermediate was shown by synthesis o f 2-oxa-6-adamantanol (19), 2-oxa-6-adamantanone (22), 2-oxa-6-adamantanamine hydrochloride (23), a n d 2-oxa-6-adamantanecarboxylic acid (26).