AIC608 161 The reaction of CpRu(C0); successively with CS2, CH31, and CF3S03H yields the cationic thiocarbonyl complex C~RU(CO)~(CS)+. This complex reacts with N; and N2H4 to give CpRu(C0)2NCS and with NCO-to yield CPRU(CO)~CN. With NaH, C~R U ( C O )~( C S ) + is reduced to a mixture of the dimeric complexes [CpRu(CO)(CS)], (major product) and Cp2Ru2(C0)3(CS). In both dimers the CS groups are in the bridging positions, and there is no evidence for nonbridged structures unlike [ C~R U ( C O )~]~ which exists partially in a nonbridged form. Infrared and proton NMR studies indicate that both [CpRu(CO)(CS)]2 and Cp2Ru2(C0)3(CS) exist in cis and trans forms which interconvert too rapidly to be separated. The presence of the bridging CS groups does, however, slow the rate of isomerization. Qualitative studies indicate that this rate decreases in the order [ C~R U ( C O )~]~ > Cp2Ru2(C0)3(CS) > [CpRu(CO)(CS)I2. Mechanisms for theseisomerizations are discussed. The preference of CS for a bridging over a terminal position in these molecules is rationalized in terms of the weakness of the C 4 r bonds which lose little r-bond stabilization in moving from a terminal ( C 4 ) to a bridging (>W) position. These arguments also suggest that CO should have a lower preference for a bridging position than CS.
Diazotization of endo-7-aminomethylbicyclo[3.3.1]nonan-exo-3-ol (3) with aqueous nitrous acid produced 3methylbicyclo[3.3.1]non-2-en-eio-7-ol (7), exo-7-methylbicyclo[3.3.1]nonan-3-one (8), and presumably exo-8-hydroxybicyclo[4.3.1]dec-2-ene (9) as major products. Exposure of endo-7-aminomethylbicyclo[3.3.1]nonan-endo-3-ol (2) to both protic (acetic acid or water) and aprotic (benzene) deamination resulted mainly in formation of 1methyl-2-oxaadamantane (19) and 4-oxahomoadamantane (20) in addition to a component tentatively identified as endo-8-hydroxybicyclo[4.3.1]dec-3-ene (21). Compound 2 yielded endo-7-aminomethylbicyclo[3,3.1]non-2-ene (4) with dilute sulfuric acid. Deamination of 4 under conditions used for 2 provided 2-adamantanol (28) and 2adamantyl acetate (29) as principal products. Elimination, transannular interactions, and apparently ring expansion comprise the dominant reaction routes. 7 gave 8 with sulfuric acid. The preparations of the isomeric 7-methylenebicyclo[3.3.l]nonan-3-ols (10) and endo-7-methylbicyclo[3.3.l]nonan-3-one (11) from reduction of 7-methylenebicyclo[3.3.l]nonan-3-one (12) are described. Endo alcohol 10b provided 19 under acidic conditions. Mechanistic aspects of the investigation are treated.
The behavior of toward various reducing agents was investigated. Sodium borohydride gave a mixture of endo and exo alcohols (mainly endo) whose ratio varied depending upon the nature of the alcohol used as the medium. Sodium-alcohol reduction provided the exo alcohol as essentially the only product. With hydrogenation in ethanol in the presence of Raney nickel, carbonyl reduction, N-alkylation, and reductive cyclization occurred. Either mono-or dialkylation on nitrogen took place depending upon the temperature. The cyclization reaction produced A-ethyl-4-azahomoadamantane. Conversion to the diamine, exo-3-amino-endo-7-aminomethylbicyclo[3.3.1]nonane, was effected by sodium-ethanol reduction of the oxime of 1. Mechanistic and conformational aspects are also treated.There are relatively few uncomplicated routes for entry into the bicyclo[3.3.1]nonane series.4"6 A simple pathway was recently reported6'7 via rearrangement of l-N,N-dichloroaminoadamantane in the presence of aluminum chloride. Subsequent exposure to aqueous acid afforded endo-7-aminomethylbicyclo[3.3.1]nonan-3-one (1) in 70-80% yield (eq 1). Prior work6•8 has shown that 1 can serve as a versatile precursor for a variety of derivatives in this series by reactions which generally take place in high yield.
Adamantanone oxime underwent Beckmann rearrangement with thionyl chloride as the promoter to produce 4-azatricyelo[4.3.1 ,l3,8]undecan-5-one in 85% yield. An investigation of reaction variables provided optimum reaction conditions and mechanistic information.
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