Bicyclic hydrocarbon derivs

Berberine alkaloids synthesis steps, 295-297 Betaines in Wittig olefinations, 29-30 Bicyclic compounds. See Oligocyclic compounds Bicyclic hydrocarbon derivs. pr., 192 Bicyclo[4.1.0]hepta-2,4-dienes rearr., 334 Bicyclo[2.2.1]heptane derivs. pr., 192... 

Some useful by-products of pulping are derived from these extractives, the most important of which are turpentine and tall oil. Turpentine is a mixture of bicyclic hydrocarbons with the empirical formula C10H16, the dominant components of which are a- and /J-pinene (Figure 2.8). They are produced as volatile by-products at a yield of around 4-5 litres per tonne of wood (for pine) and are used as a solvent and as a chemical feedstock. 

The scope of this problem can be indicated by a brief consideration of the stereochemical nomenclature of hydroxy derivatives of the bicyclic terpenes. For the parent bicyclic hydrocarbon compound known in the literature at present as cam-phane, the name "bomane is recommended in this report. (Reasons for choosing "bornane are discussed later under "The Bornane Hydrocarbons .) A mono-hydroxy derivative of bornane, on the basis of IUPAC rules (41), would be named as a bornanol. Two such derivatives have the common terpene names, bomeol and isobomeol these names, on the basis of recommendations in this report would both become 2-bornanol. Obviously, this is inadequate and additional designations are necessary to distinguish between die two stereoisomers. 

Furthermore, the use of special subgroup names such as fenchenes, which applies to a series of synthetic compounds to indicate their derivation from fenchyl and iso-fenchyl derivatives and reportedly (33) to distinguish them from closely related naturally occurring terpenes, obviously complicates the problem of systematizing nomenclature. Names such as cyclofenchene and /8-difenchene are two additional memory exercises. Such irregularities in nomenclature have, of course, been carried over into the nomenclature of derivatives of these bicyclic hydrocarbons. 

Rule 7 Form the above types of terpene-like names for all hydrocarbon terpene radicals derived from the four fundamental types of bicyclic hydrocarbons regardless of the position of the point or points of attachment that is, the H or H s may be removed from carbons in the ring or from carbons in the numbered side chains. Use position numbers to designate the position of the point or points of attachment in the radicals. 

Beginning with diethynylbenzene derivatives, it is obvious that the para-isomer 45 could lead to rod-like hydrocarbons, whereas the meta- (46) and the ortho-isomers (47), respectively, could provide angular and circular structures. Of course, an increase in the number of ethynyl groups results in an increased number of coupling possibilities. 1,3,5-Triethynylbenzene (48), for example, is of interest since it can be used for the construction of bicyclic hydrocarbons - it constitutes a blown-up version of a bridgehead. Clearly, hexa-ethynylbenzene (49) [32] can function as a tile for the preparation of novel forms of... 

Experimental measurements on the enthalpy of formation are also lacking for the saturated parent bicyclic hydrocarbon, as well as for any other substituted and/or hetero derivative, save the equally conceptually complicated l,6-oxido[10]annulene. 

Bicyclo[1.1.0]butanes (1 equation 1), the smallest bicyclic hydrocarbons, are highly strained but stable at ambient temperature. Under the influence of a catalytic amount of a nickel(0) complex, however, they undergo cleavage of the central bond and one of the four peripheral bonds and enter into cycloaddition reactions with electron deficient alkenes to afford allylcyclopropane derivatives. Reaction of... 

Among the simple cycloalkanes, we first discuss electron transfer from the three-to eight-membered cycloalkane prototypes to electron holes generated by radiolysis in different matrices, giving rise to the simple cycloalkane radical cations. Because of the significant interest they have attracted, the electron-transfer reactions of cyclopropane and, to a lesser extent, cyclobutane derivatives will be treated separately. Finally, electron transfer from some bicyclic hydrocarbons and the resulting radical cations will be discussed in a separate section (Section 2.4). 

Decahydronaphthalene - hI-( )dro- naf-tho- len (Decalin ) n. A saturated bicyclic hydrocarbon, CioHig, essentially two cyclohexane rings fused together, sharing two hydrogen atoms. The commercial product is a mixture of cis- and trans-isomers. It is a colorless liquid with an aromatic odor, derived by treating molten naphthalene with hydrogen in the presence of a catalyst. 

Molecular structures of monoterpenoids are present as three major types acyclic, monocyclic and bicyclic. Oxygenated derivatives of acyclic monoterpenes are more widespread in nature than acyclic monoterpenes themselves. Such derivatives are the monoterpene alcohols citronellol and geraniol, or the monoterpene aldehydes citronellal and geranial. Mononocyclic monoterpene hydrocarbons are exemplified by limonene, which is a major component of orange and lemon peel oils, and p-phellandrene, which is emitted by conifer trees under biotic stress. These compounds are relatively common in nature. Bicyclic monoterpenes are represented by the aforementioned a-pinene, one of the most abundant and important monoterpenes. 

It would be worthwhile to compare the behavior of bicyclo[ 1.1. OJbutane (XXIX) with that of the hydrocarbons described above. The smallest bicyclic hydrocarbon (XXIX) suffers two-bond cleavage by a nickel(O) catalyst to produce the allylcarbene-nickel(O) intermediate (XXX), which is trapped with coordinated olefins, giving the allylcyclopropane derivatives (XXXI) (Noyori et a ., 1971b, 1974d Noyori, 1973, 1975). The catalytic reaction of 3,3-... 

Of the fundamental nonalternant hydrocarbons, only two prototypes were known about fifteen years ago azulene (XI, Fig. 5), the molecular structure of which was determined by Pfau and Plattner and fulvene (XIX) synthesized by Thiec and Wiemann. Early in the 1960 s many other interesting prototypes have come to be synthesized. Doering succeeded in synthesizing heptafulvene (XX) fulvalene (XXI) and heptafulvalene (XXIII). Prinzbach and Rosswog reported the synthesis of sesquifulvalene (XXII). Preparation of a condensed bicyclic nonalternant hydrocarbon, heptalene (VII), was reported by Dauben and Bertelli . On the other hand, its 5-membered analogue, pentalene (I), has remained, up to the present, unvanquished to many attempts made by synthetic chemists. Very recently, de Mayo and his associates have succeeded in synthesizing its closest derivative, 1-methylpentalene. It is added in this connection that dimethyl derivatives of condensed tricyclic nonaltemant hydrocarbons composed of 5- and 7-membered rings (XIV and XV), known as Hafner s hydrocarbons, were synthesized by Hafner and Schneider already in 1958. 

The molecular structure of the bicyclic framework in 108 is best described as a dithiatriazine bridged by an -N=S=N- group. The aryl-substituted derivatives 108 (R=aryl) form 2 1 inclusion complexes with aromatic fluorocarbons or hydrocarbons.266 In solution, the phenyl derivative 108 (R=Ph) is fluxional.258... 

An example of the vinylogous reactivity is the reaction of 52 with cyclopentadiene (Tab. 14.9) [77]. Rhodium(II) acetate-catalyzed decomposition of 52 in dichloro-methane, yields a 2 1 mixture of the bicyclic system 53 derived from the [3-1-4] cycloaddition, and the bicyclo[2.2.1]heptene 54 resulting from electrophihc attack at the vinylic position followed by ring closure. When Rh2(TFA)4 is used as the catalyst, bicy-clo[2.2.1]heptene 54 becomes the dominant product, while the reactivity of the vinyl terminus is suppressed using a hydrocarbon solvent as observed in the Rh2(OOct)4-cat-alyzed reaction in pentane, which affords a 50 1 ratio of products favoring the [3-1-4] cycloadduct 53. 

The thermochemical data are likewise sparse for the methylene derivatives of the bicyclic and polycyclic ketones. For these species, we consider the difference quantity <540 which is defined as the difference of the gas-phase enthalpies of formation of the ketone of interest and the related hydrocarbon ... 

The monocyclic terpene hydrocarbons, many of which are formed readily from the acyclic terpenes by ring closure or from the bicyclic terpenes by ring fission, contain a six-carbon ring and may all be considered as derivatives of either cyclohexane or benzene. They may also be classified, on the basis of common larger fundamental structures, into two distinct types of substituted six-carbon ring structures ... 

Despite the early recognition of the four fundamental bicyclic structures and the agreement on their class names, no attempts seem to have been made to replace the many historical terpene names for the bicyclic terpene hydrocarbons and their derivatives by simple, logical series of names for each type. The terpene chemist s attitude in the thirties on nomenclature of the bicyclic terpenes has been summarized by Lipp (32) as follows ... 

Thujane Group (Bicyclo Q3.1. O hexane Type). Name the thujane-type bicyclic terpene hydrocarbons (bicyclo 3.1. (T] hexane type) as thujanes, thujenes, and thu-jadienes, and base these names on the recommended fixed numbering of the thujane carbon skeleton. (Formula 46, Chart 10). For those derivatives which contain (1) fewer carbon atoms than thujane, (2) the same number as, or more carbon atoms than thujane but do not have a carbon skeleton identical to that of thujane, or (3) more carbon atoms than thujane and a carbon skeleton identical to that of thujane but contain substituents such that the principle of like treatment of like things will be violated by using the thujane, thujene, and thujadiene names, use the bicyclo 3.1 (T]-hexane-type names based on systematic bicyclo numbering (Formula 43, Chart 10). 

The bicyclic terpene hydrocarbons classified in this report as the bomane group (bicycloQ2.2.1 heptane type), but currently called the camphane group in terpene literature, are more numerous and have many more important derivatives (especially the camphors) than the other three fundamental bicyclic types — the thujane, carane, and pinane groups — already discussed. As would be expected, a greater variety in the arrangement of substituents and double bonds and in the number of substituents is found. 

These and other considerations led directly to the recommended name bomane group for the group of bicyclic terpene hydrocarbons currently called the camphane group. Specific recommendations on continued usage of the common terpene names of bornane-type bicyclics are being withheld until a more thorough study has been made of the nomenclature of their derivatives. 

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