ISSN:
1434-193X
Keywords:
2,8-Didehydronoradamantane derivatives
;
Cyclopropylcarbinyl
;
Rearrangements
;
Ring-opening reactions
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
-2,8-Didehydronoradamantan-9-one (2) was readily prepared by oxa-di-π-methane photorearrangement of brend-4-en-2-one (1). Other new 9-substituted 2,8-didehydronoradamantanes have also been prepared from 2, [i.e. 2,8-didehydronoradamantan-9-ol (3) and tosylhydrazone 4] and the ring-opening reactions have been studied. In acidic media, 2,8-didehydronoradamantan-9-ol (3) rearranges to the corresponding 2-substituted brend-4-ene derivatives. Exclusive formation of exo-2-substituted brend-4-enes supports the formation of a bridged bicyclobutonium ion. However, treatment of ketone 2 with PCl5 proceeds through a concerted mechanism by cleavage of the C-1-C-2 bond in 2 to give exo-2,5-dichlorotricyclo[4.2.1.03,8]non-4-ene (6). The tricyclo[4.2.1.03,8]nonane skeleton was also obtained by photochemically induced electron transfer reduction of 2 and reduction of 2 with Li/NH3, as well as by reduction of tosylhydrazone 4 with both NaBH3CN and BH3 × THF. On the other hand, Wolff-Kishner reduction of 2 gave the non-rearranged product, 2,8-didehydronoradamantane (10).
Type of Medium:
Electronic Resource
