Single atom, peri-bridged arenes: 1-alkylidene-1H-cyclobuta[de]naphthalenes and .DELTA.1,1-bi-1H-cyclobuta[de]naphthalene

Molecular and Electronic Structure of 1,8-Peribridged Naphthalenes

The crystal and molecular structure of 1,8-thianaphthalene has been determined and compared with other single-atom peribridged naphthalenes (SAPN). The measured CSC angle is 73.06 degrees, which is the smallest bridging angle yet recorded for a SAPN derivative. The ab initio calculations using G3(MP2)//B3LYP method were performed for peribridged naphthalenes in order to determine how the strain of the four-membered ring is influenced by the type of bridge linking 1,8 positions. The electronic structure of 1,8-thia- and 1,8-sulfonenaphthalenes has been studied by UV photoelectron spectroscopy. We have tried to identify and distinguish the strain effect on the electronic structure of the naphthalene moiety.

Photolytic, Thermal, Addition, and Cycloaddition Reactions of 2-Diazo-5,6- and -3,8-disubstituted Acenaphthenones

Preparation and varied thermal and photolytic reactions of 2-diazo-5,6-(disubstituted)acenaphthenones (11a-d) and 2-diazo-3,8-dimethoxyacenaphthenone (12) are reported. Alcohols react thermally and photolytically with 11a-c with losses of N(2) to yield 2-alkoxynaphthenones (24a,band 47a,b) and acenaphthenones (25 and 48a,b). Aniline and diphenylamine are converted by 11a-c at 180 degrees C to acenaph[1,2-b]indoles (29a,b and 53a,b). Thermolyses of 11a-c at approximately 450 degrees C (0.15 mmHg) yield reduction products 25 and 48a,b, respectively. Wolff rearrangements to 1,8-naphthyleneketenes (15a-d) and/or their derivatives are not observed in the above experiments. Oxygen converts 11a-c thermally to acenaphthenequinones (19a-c) and/or 1,8-naphthalic anhydrides. Insertion, addition, substitution, and/or isomerization reactions occur upon irradiation of 2-diazoacenaphthenones in cyclohexane, benzene, and tetrahydrofuran. Photolysis of 11d in benzene in the presence of O(2) yields the insertion-oxidation product 2-hydroxy-5,6-dinitro-2-phenylacenaphthenone (60). Photolyses of 11a-c in nitriles result in N(2) evolution and dipolar cycloaddition to give acenaph[1,2-d]oxazoles (41 and 61a,b). Acetylenes undergo thermal and photolytic cycloaddition/1,5-sigmatropic rearrangement reactions with 11a-d with N(2) retention to give pyrazolo[5,1-a]quinolin-7-ones (69f-j). 2-Diazoacenaphthenones 1a and 11a react thermally and photolytically with electronegatively-substituted olefins with N(2) expulsion to yield (E)- and (Z)-2-oxospiro[acenaphthylene-1(2H),1'cyclopropanes] 73a-c and 74a-c, respectively. The mechanisms of the reactions of 1a, 11a-d, and 12 reported are discussed.