Pinane derivs

This principle represents both British and American practice, and has been followed for some years. Although a name such as methylpinane violates this principle, it is unambiguous and simpler than tetrametbylnorpinane. Also, relations among substituted pinane derivatives are more readily seen horn a series of names such as methylpinane, (chloromethyl)pinane, and methylenepinane than from a series in which methylpinane is replaced by tetrametbylnorpinane. The names of only a few terpene compounds are involved, however, in this problem and a compromise may be the best solution. For the sake of consistent nomenclature between terpenes and related compounds, sticking to a recognized principle is an important consideration. 

The cavity volume varies from 190 to 390 A3 and the average size of the guest is in the range 160-225 A3 for camphor derivatives and 145-175 A3 for pinane derivatives. Therefore, the proper matching of host and guest was crucial to obtain complexes characterized by the proper fitting and packing... 

Asymmetric allylboration using tartrate- and pinane-derived reagents have been successfully exploited in the synthesis of various natural products.653-673... 

Rate constants and activation energies for liquid- and gas-phase isomerization of a-pinene have been determined.310 The activity of metal sulphate monohydrates in isomerizing a-pinene is correlated with the strength of co-ordination of the water of crystallization to the metal ion.3" Pyrolysis of chrysanthanol acetate (217 R = Ac) gives citronellal and the (E)- and (Z)-3,7-dimethylocta-l, 6-dien-l -ol acetates in 20, 28, and 3% yields respectively formation of the enol acetates is consistent with a biradical or a concerted pathway.312 Further work directed towards C-l—C-7 bond pyrolysis of pinane derivatives shows C-l—C-7 C-l—C-6 bond cleavage ratios of 4 51 for (217 R = Ac), 13 22 for (217 R = H), 6 7 for (218 R = H), and 43 35 for (218 R = Me) the expected acyclic and cyclic alcohol, aldehyde, and ketone pyrolysis products are obtained.313 The ene reaction between /3-pinene and methyl... 

Katsura, M., Miyamoto, T., Hamanaka, N., Kondo, K., Terada, T., Ohgaki, Y., Kawasaki, A. and Tsuboshima, M. (1983). In vitro and in vivo effects of new powerful thromboxane antagonists (3-alkylamino pinane derivatives). Adv. Prostagl Thrombox. Leuk. Res., 11, 351-357... 

Allylation of carbonyl compounds is another very useful carbon-carbon bond forming asymmetric transformation in organic synthesis. This transformation yields the homoallylic alcohols that have proven to be valuable reagents and intermediates that have found numerous applications in natural product total synthesis. In particular, asymmetric allyl-boration of aldehydes employing tartrate- and pinane-derived reagents has been widely exploited. Although the asymmetric allylation reaction is well documented and widely used in solution phase, the asymmetric variant of the allylation of carbonyl compounds on the solid support has remained largely unexplored. ... 

Several oxygenated derivatives based on pinane have been found to occur in woody parts. For example, myrtenol (100), myrtenal (101) and myrtenic acid (102) have been isolated from wood of Chamaecyparis formosensis. (-)-trans-Pinocarveol (103) is present in American gum turpentine. (+)-c/5 -Verbenol (104), its trans isomer, and (+)-tra/w-verbenone (105) are important components of frankincense from Boswellia cartevii (275 vol. Ill b, c, 296, 379). From the roots of Paeonia albiflora, a few highly oxygenated pinane derivatives (e.g., paeoniflo-rin, 106) have been obtained (223). 

Stereoselective alkylation with aliphatic bromides and iodides of the Schiff bases of tert-butyl glycinate with (—)-(15,25,55)-2-hydroxypinan-3-one or (+)-(lR,2R,5R)-2-hydroxy-pinan-3-one 150 was reported to produce lipidated amino acids as d- and L-enantiomers in 80 to over 90% ee. 151 Similarly, the asymmetric synthesis of a derivative of arachidonic acid (4) has also been reported. The pure enantiomer was obtained via regioselective functionalization of a chirally pure glutamic acid. 152 ... 

Also the biotransformation of a-pinene derivatives and other pinane monoterpenoids by Cephalosporium aphidicola has been described [101]. The best conversion was the oxidation of verbenol to verbenone (yield 61%). 

Among several dipyridine derivatives developed as chiral ligands, a Rh catalyst with phenanthroline 13b having a pinane skeleton gave 4 with 76% ee in the reduction of 1, which was higher than that obtained with Rh-phenanthroline-oxazoline 13a [20], whereas the tetraden-tate dipyridine-bis(oxazoline) Bipymox 14 in combination with RhCl, gave 4 with 90% ee (S) [21]. 

Cyclic epoxide derivatives, such as 2,3-epoxy-c/s-pinane 210 [Eq. (5.299)]826 and isomeric caryophyllene diepoxides 211 [Eq. (5.300)],827 undergo varied transformations including ring contraction under similar conditions. 

Pinane Group (BicycloQ3.1 JT]heptane Type). Name the pinane-type bicyclic terpene hydrocarbons (bicyclo 3.1.Y beptane type) as pinanes, pinenes, and pina-dienes, and base these names on the recommended fixed numberings of the pinane carbon skeleton (Formula 66, Chart 12). For those derivatives which contain (1) fewer carbon atoms than pinane, (2) the same number as, or more carbon atoms than, pinane but do not have a carbon skeleton identical to that of pinane, or (3) more carbon atoms than pinane and a carbon skeleton identical to that of pinane but contain substituents such that the principle of like treatment of like things will be violated by using the pinane, pinene, and pinadiene names, use the nor- type of terpene names based on systematic bicyclo numbering (Formula 59, Chart 12). See Chart 12. 

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. 

Allowing the addition of one carbon atom, or at most only two, to a terpene parent compound carbon skeleton for naming compounds as derivatives of that parent" (proposed by L. A. Goldblatt). This principle does not depend on a distinction between like and unlike groups, but is based merely on the number of carbon atoms in the substituents. Therefore, it allows such names as methylpinane, methylenepinane, (chlorometbyl)pinane, and (if two additional carbons are allowed) ethyl-pinane. The first of these four types of names are not allowed by either Proposal I or Proposal II. The other three types are allowed by I but not by II. 

The name pinanyl is recommended for the univalent saturated radical (CjqH ij-j derived from pinane because in the terpene literature the name pinyl (which would be the name formed by replacing the ending ane of pinane by yt) has been used exclusively and frequently for a 10 15—radical (with point of attachment at position 3) derived from /S-pinene. Since pinanyl must be an exception to the general rules, the names of the other two saturated radicals in the pinane-group series, that is, pinanylidene and pinanylene, should also be exceptions for consistency. In the series of nor- names, however, it does not seem necessary to insert the "an syllable because the radical names norpinyl and the like have not been used in the literature. 

The most abundant and widely used monoterpenes, pinenes and their analogues, are often upgraded to more sophisticated structures with a Robinson annelation as the key step. However, as a result of unusual stereochemical constrains imposed by the bicyclic ring, only certain conformational isomers of the pinane skeleton undergo the annelation. Whereas the diketone (41) derived from n. v-inethylnopinone cyclized satisfactorily to the tricyclic ketone under Robinson conditions (Scheme 5.18), the epimeric diketone would not.64... 

A second synthesis of chiral grandisol (73) from trans-pinan-2/3-ol (77 X = H) derived from (—)-/3-pinene, as shown in Scheme 8, involves the useful photochemical... 

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