Metacyclophanes and related compounds. 14. Preparation of 8,16-difluoro[2.2]metacyclophane
作者:Masashi Tashiro、Takehiko Yamato
DOI:10.1021/jo00216a026
日期:1985.8
Metacyclophanes and related compounds. 22. Medium-sized cyclophanes. Preparation and valence tautomerism of 8,16-disubstituted [2.2]metacyclophane-1,9-dienes
作者:Takehiko Yamato、Akira Miyazawa、Masashi Tashiro
DOI:10.1021/jo00027a047
日期:1992.1
Introduction of functional groups other than hydrogen or alkyl groups into the internal positions of [2.2]metacyclophane-1,9-dienes was attempted. [2.2]Metacyclophane-1,9-dienes 6a-6g, bearing variously halogen, methoxy, and methyl substituents in the 8 and 16 positions, were prepared from the corresponding bis(halomethyl)benzenes 1 and bis(mercaptomethyl)benzenes 2 involving use of Wittig rearrangement of 2,11-dithia-[3.3]metacyclophanes followed by Hofmann elimination. Although 6a-6c, 6f, and 6g were isolated as thermally stable crystals, isolation of 6d failed since this compound was thermally labile and transformed spontaneously into 2,7-di-tert-butyl-1-chloropyrene (7). The photochemical and thermal valence tautomerizations of [2.2]metacyclophanes which were prepared in the present work are described. Attempts to convert 8,16-disubstituted [2.2]metacyclophane-1,9-dienes 6 to 4,5,9,10-tetrabromo-10b,10c-disubstituted 10b,10c-dihydropyrenes by treatment of these compounds with bromine in carbon tetrachloride failed but instead gave addition products 13 and transannular reaction products 14. The reaction pathways of the bromination are also discussed.
TASHIRO, MASASHI;YAMATO, TAKEHIKO, J. ORG. CHEM., 1985, 50, N 16, 2939-2942