Bicyclo decanes

FIGURE 1.10 Two isomers of decahydronaphthalene, or bicyclo[4.4.0]decane. (a) Trans isomer b) cis isomer. 

The bicyclic compound decahydronaphthalene, or bicyclo[4.4.0]decane, has two fused six-mem-bered rings. It exists in cis and trans forms (see Fig. 1.10), as determined by the configurations at the bridgehead carbon atoms. Both cis- and rran -decahydronaphthaiene can be constructed with two chair conformations. 

N,N -linked synthesis, 5, 269 6,6 -Biazulenes synthesis, 1, All Bibenzimidazolyls 3-oxides synthesis, 5, 412 1,1 - Bibenzimidazolyls synthesis, 5, 459 2,2 -Bibenzo[b]selenienyl synthesis, 4, 947 2,2 -Bibenzothiazolyl reduction, 6, 260 4,4 -Bichromenyl synthesis, 3, 743 Bicyclo[n. 1.0]alkanes retro-cycloaddition reactions, 1, 668 Bicyclo[5.3.0]decane synthesis, 1, 420 Bicyclo[4.1,0]diheteroheptanes synthesis, 3, 977... 

The decalin (bicyclo[4.4.0]decane) ring system provides another important system for study of conformational effects in cyclohexane rings. Equilibration of the cis and trans isomers reveals that the trans isomer is favored by about 2.8 kcal/mol. Note that this represents a change in configuration, not conformation. The energy difference can be analyzed by noting that the cis isomer has three more gauche butane interactions that are... 

Chemical Designations - Synonyms Bicyclo [4.4.0] Decane Naphthalane Perhydronaphthlene Dec Decalin De Kalin Naphthane sic- or trans-Decahydronaphthalene Chemical Formula CjoHu. Observable Characteristics - Physical State (as normally shipped) Liquid Color Colorless Odor Aromatic, like turpentine mild, characteristic. 

Among the most important of the bicyclic hydrocarbons are the two stereoisomeric bicyclo[4.4.0]decanes, called cis- and rrani-decalin. The hydrogen atoms at the ring junctions are on the same side in c/5-decalin and on opposite sides in tmns-AecdXm. Both rings adopt the chair confonnation in each stereoisomer. 

Die reduktive Alkylierung kann aueh intramolekular durchgefiihrt werden6. Aus 2,4-Dipiperidyl-(2)-butansaure-athylester wird neben 2,4-DipiperidyI-(2)-butanol 34% d. Th. 3-Piperidyl-(2)-l-aza-bicyclo[4.4.0]decan erhalten7 ... 

Ct 0 COOCH3 NafBHJ 10-Hydroxy-1,6-di-methyl-2-methoxycarbonyl-bicyclo [4.4.0]decan 91 (F 71-74°) 2... 

Die Spaltung von Tetrahydro-l,3-oxazinen zu 3-Amino-alkoholen kann mit Li-thiumalanat durchgefiihrt werden2,3 z.B. 5-Oxa-l-aza-bicyclo[4.4.0]decan zu 3-Piperi-dino-propanol (77% d.Th.)4 ... 

A mixture of decalin (bicyclo[4.4.0]decane) isomers (Fluka, >98%) with a cis-to-trans ratio of 2-to-3 was used as a starting material. The experiments were performed in an electrically heated 300-mL stainless steel autoclave (Parr Industries) at 523 K and 2 MPa. The stirring rate and the starting material-to-catalyst ratio were kept at constant values equal to 1500 rpm and 22 (w/w), respectively. The screened catalysts were crushed and the fraction bellow 63 pm was used in the experiments to suppress internal diffusion. 

Intramolecular cyclopropanation of 4-aryl-1 -diazo-2-butanones 240 allows construction of the bicyclo[5.3.0]decane framework 12). In a reaction sequence analogous to that described above for the intermolecular ketocarbenoid reaction, bicyclo-[5.3.0]deca-l,3,5-trien-8-ones 241 are formed. They rearrange to the conjugated isomers 242 at the high temperatures needed if the reaction is catalyzed by copper 2311 or CuCl 232), but can be isolated in excellent yield from the Rh2(OAc)4-promoted reaction which occurs at lower temperature 233... 

Synonym bicyclo[4.4.0]decane, naphthalane, naphthane Chemical Name decahydronaphthalene (mixed isomers)... 

Bicyclo[4.4.0]decane, d2, d3 Bicyclo[5.3.0]decapentane, a316 Biformyl, g28 Biphenol, d436... 

Rhodium-catalyzed [5 + 2]-cycloaddition of an allene and a vinylcyclopropane proceeds with complete chemo-, endo/exo- and diastereoselectivity, representing an effective general route to bicyclo[5.3.0]decane derivatives (Scheme 16.75) [81]. This cydoaddition protocol has been applied successfully to asymmetric total syntheses of natural products [82, 83]. 

Intraactions between elections in three-membered rings and unsaturated groups in the same molecule have been detected via 13C chemical-shift variations in a number of instances. Thus, introduction of the carbonyl function in tricy-clo[3.2.1,02,7]decane (e.g., 274) leads to significant downfield shifts of the signals of C(l) (+8.0), C(2) (+15.5), and C(7) (+7.7) (385), whereas corresponding effects in bicyclo[3.1.0]hexan-2-one (275) are smaller (385,386). A corresponding dependence was reported for 276 and 277 and related to more effective electron withdrawal in 276 (387). An even more pronounced deshielding effect was observed by Murata and co-workers (388,389) in the ketone 278 when they compared it with 279. 

Bisher rniBlangen die Versuche, bicyclische Azazulene lierzustellen. Sowohl das von V. Prelog und U. Geyer (107) synthetisierte 8-Aza-bicyclo-(0,3,5)-decan, wie das von J. O. Halford und B. Weissmann (48) beschriebene 4-Azabicyclo-(0,3,5)-decan widerstanden den bekannten Dehydrierungsmoglichkeiten. 

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