Hart, H; Shamouilian, S; Takehira, Y
simple one-step synthesis of triptycene analogues prepared by reaction of a diaryne equivalent with anthracenes is described. For example, 1,2,4,5-tetrabromobenzene, anthracene, and n-butyllithium gave 5,7,12,14-tetrahydro- 5,14[lâ,2']:7,12[ 1â,2â]-dibenzenopentacene (2, R = H.; trivially called a p-pentiptycene) in good yield. Other tetrabromoarenes were used to similarly prepare 2 (R = CH3), 2 (R = OCH3), and the naphtho analogue 13. Use of 9,10-dimethoxyanthracene gave the tetramethoxy bridgehead-substituted pentiptycene 11. 4,5-Dibromo- 3,6-diiodo-o-xylene functioned as an ortho diaryne equivalent to give the o-pentiptycene 3 (R = CH3). The synthesis of heptiptycene 4 (5,6,ll,12,17,18-hexahydro-5,18[lâ,2']:6,ll[lâ,2â]:12,17[l,â,2,â]-tribenzenotrinaphthylene has been improved, and the intermediate cycloalkyne 22 has been trapped with various dienes. © 1981, American Chemical Society. All rights reserved.