Tryptycenes

More recent examples of experiments with sterically congested molecules are Mylroie and Stenberg s hydrogenation of the sterically hindered substituted tryptycenes,60 and hydrogenation of the double bond in tetraethyl bicy-clo[2.2.2]oct-7-ene-2-syn,3-syn,5-syn,6-syn-tetracarboxylate (4) which occurs over 5% Pd/C in ethyl acetate at room temperature and under 1 atm of hydrogen in 48 hours.61... 

Tryptycenes can be chiral, but how can one determine the absolute configuration The CD of (+)-dimethyl 5,12-dihydro-5,12[1, 2 ]benzonaphthacene-l, 15-dicarboxylateshows an intense (+) chirality exciton couplet (Ac +151, Aeffo -178) for the intense (emax -84,000) 233 nm transition. As with the pyranosides, the binary couplets must be... 

Dehydrobenzene also functions as a philodiene, as may be illustrated by the synthesis of tryptycene described by Wittig and his co-workers 42,50... 

Reaction of anthracene (42 mmoles) and o-bromofluorobenzene (30 mmoles) with magnesium in tetrahydrofuran affords a mixture of hydrocarbons. This is first freed from unchanged anthracene by treatment with maleic anhydride. Chromatography then affords 11 % of triphenylene (m.p. 194-195°) and 28 % of tryptycene (m.p. 255-256.5°). Formation of the latter occurs as follows ... 

A series of tryptycene-derived homooxacalixarenes (6) was conveniently prepared by a one-pot approach starting from 2,7-dihydroxytriptycene and l,3-bis(bromomethyl)benzene derivatives under mild conditions (13JOC981).Tryptycene-derived macrotricyclic polyethers containing two dibenzo [30] crown-10 cavities and different functionalized paraquat derivatives, diquat, and a 2,7-diazapyrenium salt in both the solid state and in solution were studied (13JOC3235). The first organometallic (Pd) complexes of an oxacalixarene were prepared by oxidative addition of the C-I bond on the lower rim (13IC6779). 

RCOaH - PhaSnCOaR with 1-apocamphane, 1-norborane, 1-tryptycene, 2-pyrrole acids... 

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