The 18C NMR spectra of 7-heterotetracyclo[4.1.0.02.'.08.5]heptanes and of the 7-methyl-and 7-phenyltetracyclo[4.1.0.0U.os.&]heptanea have been measured, and the three-membered-ring annelation effects were determined. The unusual deahielding found for the C-3 resonance in a cyclopropane-annelated cyclopentane derivative (bicyclo[3.1.0]hexane derivative) in the chair conformation carries an even stronger effect in the analogous aziridine-, omene-, and thiirane-annelated systems. Substituents in the 7-poeition oftetracyclo

The reaction of bennalene (4) with tetracyanoethylene (TCNE) affords a mixture of tetracyclo[ 3.3.0.02~4.03~6]o~tane derivative 5, tricycl0[3.3.0.0~~~]oct-7-ene derivative 6, and tricycl0[3.3.0.0~~~]oct-6-ene derivative 7. By means of dideuterated benzvalene 4a and the solvent effect on the ratio of the products the mechanisms have been studied. Accordingly, the formation of the main products 5 and 6 involves zwitterionic intermediates, which arise from electrophilic attack of TCNE at the olefinic portion of 4. The third compound 7 is thought to be produced in a concerted 1,4-addition of TCNE to the vinylcyclopropane moiety of benzvalene (4). Treatment of 4 with 2,3-dichloro-5,6-dicyano-p-benzoquinone gives rise to a 1:l adduct, which is structurally analogous to TCNE adduct 7 and which is most probably formed in a one-step process as evidenced by the positions of the deuterons when 4a was utilized. In a reinvestigation of the reaction between chlorosulfonyl isocyanate and 4 the new compounds 18a, a 4-azatricycl0[3.3.0.0~*~]oct-6-en-3-one derivative, and 19, an 8-azatetracycl0[4.2.0.O~~~.O~~~]octan-7-one derivative, have been discovered in addition to the known products 2a and 3a. Even at low temperatures benzvalene (4) and sulfur dioxide react to give a mixture of the four-membered ring sulfone 23 and the sultine 24, with the ratio being dependent on the solvent polarity. That 23 is not the precursor of 24 follows from rate measurements, according to which the rearrangement 23 -24 is much slower than the formation of 24 from 4 and SO2. The experiment utilizing dideuterated benzvalene 4a has revealed a competition between two processes, a concerted 1,4-addition of SO2 to the vinylcyclopropane system of 4 yielding 23 and an electrophilic attack of SO2 at C-1 (C-6) of 4 with formation of the zwitterion 25 with a sulfinate function and an allyl cation moiety. The latter species cyclizes with almost the same rates via an oxygen atom or the sulfur atom to give rise to 2 4 and another portion of 23, respectively. In the stepwise processes TCNE and SO2 approach 4 at different sites. This phenomenon is discussed in terms of the HSAB principle. Due to its high-lying H O M O benzvalene (4) reacts with numerous electrophiles.2 In most cases the attack takes place at the double bond since the H O M O is largely localized there.3q4 Exceptions are the protonation5-' and the mercuration8 generating products, which indicate addition of the electrophile to the bicycle[ 1.1 .O] butane skeleton. Also, Ag' and several metals interact with the u system and catalyze automerizations of 4 and, finally, isomerizations to benzene and fulvene, respe~tively.~ Katz and co-workers have studied the reactions of 4 with 4-Tetracyanoethylene Results. Tetracyanoethylene (TCNE)'* resembles PTADI2gJ3 and CSII4 in that it frequently gives rearranged adducts with ~ ~-(12) (a) Loffler, H. P.; Martini, T.; M U S S~, H.; Schroder, G. Christl, Brunn, and Lanzendorfer L . 5 L.0 3.5 3.0 2.5 (17) Prinzbach, H.; Hagemann, H.; Hartenstein, J. H.; Kitzing, R. C...

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daB Metallionen bevorzugt die Phosphatsauerstoffatome in ternaren Enzym-Metallion-ATP-Komplexen koordinieren. 1 ,iO-Phenanthrolin kann als einfaches Model1 fur ein Enzym dienen, das M(ATP)'-fester als Mz+ oder ATP4-allein bindet, z. B. das System Arginin-Kinase/Mn(ATP)2-(71. Dann deuten die vorliegenden Ergebnisse auch darauf hin, daB Charge-Transfer-Wechselwirkungen bei der erhohten Stabilitat von Enzym-M2 + -ATP-Komplexen eine bedeutende Rolle spielen konnten. Arbeitsvorschrifr [' I Prof. Dr. H. Schafer, Dr. G . Cordier Abteilung 11 fur Anorganische Chemie im Eduard-Zintl-Institut der Technischen Hochschule HochschulstraBe 4, D-6100 Darmstadt Fonds der Chemischen lndustrie untentiitzt. I**] Diese Arheit wurde von der Deutschen Forschungsgemeinschaft und dem 1' 1 Prof. Angew. Chem. 93 (1981) Nr. 5 ["I Die= Arbcit wurde von der Alexander-von-Humboldt-Stiftung durch ein Stipendium (J. T.) unterstiitzt. Wir danken H e m K. Schneider fiir seineHilfe bei den Experimenten.

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