Bicyclooctane Derivatives

Reaction studies have been extended to six-membered cyclic dienes to generate bicyclooctane derivatives ... 

Bicyclooctane derivatives are also classified with the isocyclic compounds. An example of a material which has a nematic phase, in the temperature range 104-106 °C, is... 

Coyle and Bryant have reported the efficient synthesis of a triazabicyclo[3.3.0]octane system by the photocyclization of hydantoin derivatives. Thus irradiation of (295), synthesized by standard Mannich procedures, afforded the bicyclooctanes (296) in moderate to good yields. The process, akin to Norrish Type II behaviour, is a 1,6-hydrogen transfer followed by bonding in the resultant biradical (297). The bis-Mannich base compound (298) also photocyclizes, yielding (299). Coyle and his co-workers have also successfully applied the known reactivity of phthalimides to yield polycyclic compounds. Thus irradiation of (300) affords the cyclized compound (301). This can be converted into the protoberberine alkaloid skeleton (302) by treatment with aqueous HCl. The crown ether analogues (303) and (304) have... 

The photochemical addition of ethene at 0°C in methylene chloride to the enedione (77) affords a high yield of the adduct (78). This was converted to the monochloro derivative (79) which also undergoes photoaddition of ethene to yield the Z> adduct (80). This on elimination of HCl yielded the quinol (81) which can be oxidised to the quinone (82). Cycloaddition of alkenes (cyclopentene, cyclohexene, and cycloheptene) has been carried out to the same enedione (77) to yield the adducts (83). lyoda et al. have also described a convenient synthesis of the bicyclo-octanediones(84) by a photochemical addition of alkenes to the enedione (77). The adducts (84) can be reduced by zinc in acetic acid to the desired products. Cycloaddition of ethyne to the same enedione followed by reduction affords the bicyclooctanes (85). The photoaddition of alkenes to the dibromo-enedione (86) is also effective and yields, after reduction, the adducts (87). 

PdCl2, 1.1 equiv AgBp4, room temperature, then NaBlLj) to provide 93a. TheiV-methyl derivative 92b also cyclized cleanly, ruling out a mechanism involving iV-palladation followed by rearrangement to a C(2)-palladated species. Indole 94, with one additional carbon in the linker between the indole and the bicyclooctane moiety, cyclized to form both 95 and 96. Oxindole 96 likely arose from palladation-cyclization at C(4), followed by air oxidation. Lastly, indole 97, featuring an exocyclic alkene, underwent the palladium(II)-mediated cyclization to afford compound 98 in good yield. 

Tropane alkaloids comprise a large group of bases occurring predominantly in the family of the Solanaceae. Structurally they are esters of carboxylic acids with tropine (3-hydroxy-8-aza-8-methyl-[3.2.1]-bicyclooctane) and are biosynthetically derived from amino acid and acetate precursors. Despite the relative structural simplicity of the alkaloids, their biosynthesis is not well understood from a mechanistic point of view. In this article the available information pertaining to this question is summarized and discussed in context with the information that is available from the analogous pelletierine class of alkaloids. A new proposal for the mechanism of assembly of the acetate derived C, fragment of these alkaloids is introduced. 

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