Tricyclo heptane, 1,7-dimethyl-7-

Propadien 1-Cyclohexyl- V/2a, 1016 Propin 3-Cyclohexyl- V/2a, 320 f. Tricyclo[4.1.0.011 (heptan 3,6-Dimethyl- E19b, 465f. (Ring-schluB)... 

Dimethyl-3-ethoxycarbonyl-l-isopropyl- E6a, 640 [RN = CH-CH(NHR)-CH3 4 H3C-CO-CH2-COOR] 3H-Pyrrol 2-(2-Ethoxycarbonyl-ethyl)-3-isopropyliden-3,5-dihydro- E14b, 258 (En —A —C = N—OH/Cyclis.) Tricyclo[2.2.1.02 s]heptan 3-Butyl-aminocarbonyloxy- E17b, 1873 (Bicyclo[2.2.1]heptadien 4 R-NH2/C02)... 

The analogous 2,2 -blpyridyl-[2,2-dimethyl-3-(2,2-dimethylcyclopropyl)cyclopropyl]phen-oxynickel (15) is obtained in 77% yield from a,a -bipyridyl-5-nickela-3,3,7,7-tetramethyl-exo-tricyclo[4.1.0.0. " ]heptane (13) upon treatment with phenol. Methanolysis of 15 gives a 70% yield of bi(2,2-dimethylcyclopropyl) (14). Direct acidolysis of 13 with hydrochloric acid or malonic acid is also possible and leads to the same hydrocarbon product 14 in even higher yield (91%). When 13 is treated with triphenyl phosphite at 60°C, three hydrocarbons are formed. Besides the cyclodimer 4 (3%), bi(2,2-dimethylcyclopropyl) (14, 6%) and 3-methyl-l-(2,2-dimethylcyclopropyl)buta-l,3-diene (16, 15%) have been identified. ... 

When 3,3-disubstituted cyclopropenes are treated with transition metal catalysts in the presence of carbon monoxide, carbonylated cyclodi- and cyclooligomerization products are obtained either solely or in addition to homo-cyclodi- and homo-cyclotrimers. The carbonylation products 3,3,7,7-tetramethyl-exo-tricyclo[4.1.0.0 ]heptan-5-one (2) and 4-isopropyl-6,6-dimethyl-bicyclo[3.1.0]hex-3-en-2-one (3) are formed as major products from 3,3-dimethylcyclopropene and carbon monoxide with tetracarbonylnickel as catalyst at ambient pressure and 20°C. Increasing the carbon monoxide pressure to 4.5-5.25 x 10" Torr leads to increased selectivity for the formation of 2 which is obtained in 54% yield along with a 24% yield of ketone 3. 

Silver-initiated ring cleavage of bicyclo[1.1.0]butanes in protic solvents leads predominantly to mixtures of cyclopropanes and the corresponding dienes, e.g. a mixture of the norcarane ether 32 and the corresponding homoallylic ether 33 is observed in the reaction of 2,6-dimethyl-tricyclo[4.1.0.0 ]heptane (31) with silver perchlorate. This reaction is of little practical value for the synthesis of cyclopropane derivatives from bicyclo[1.1.0]butanes. 

In a similar fashion 1,2,2-trimethylbicyclobutane (29) reacted in methanol under irradiation in the presence of naphthalene-l-carbonitrile to give three products that corresponded to those obtained with dimethylated tricyclo[4.1.0.0 ]heptane system. In addition, cleavage of the bond between the quaternary carbon atoms was observed. 

Verschiedene fur die Synthese von Riechstoffen erforderliche Aldehyde lassen sich durch Hydroborierung von 1-Alkinen herstellen178. Aus der Alkin-Verbindung I entsteht Tri-cycloekasantalal l,7-Dimethyl-7-(2-formyl-ethyl)-tricyclo[2.2.1.02,6]heptan in 60%iger Ausbeute179 ... 

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