Unsaturated hydrocarbon macrocycle

Stoddard and co-workers [45-47] describe the synthesis of cyclic and linear ribbon-type oligomers starting from the monomers 21 [39] and 23 [42]. The double stranded macrocycles, e.g. 27, generated are intermediates in the preparation of cyclic oligoarenes (cycloacenes) - attractive compounds with two dimensional cyclic J7-systems of the Huckel-type. Synthetic approaches to remove the oxo-bridges reductively and to generate the final fully unsaturated hydrocarbons, lead only to intermediates, e.g. 28, which are partially hydrogenated [46]. 

Other commonly occurring chemical groups ia essential oils iaclude aromatics such as P-phenethyl alcohol, eugenol, vanillin, ben2aldehyde, cinnamaldehyde, etc heterocycHcs such as iadole (qv), pyra2iaes, thia2oles, etc hydrocarbons (Liaear, branched, saturated, or unsaturated) oxygenated compounds such as alcohols, acids, aldehydes, ketones, ethers and macrocyclic compounds such as the macrocyclic musks, which can be both saturated and unsaturated. 

Dieckmann condensation followed by hydrolysis-decarboxylation to give the unsaturated macrocyclic ketone 9-cycloheptadecen- 1-one, whose cis form, civetone, is an attractive perfume component [4,5] equation (2). Moreover, unsaturated dicarboxylic esters and acids are interesting starting materials for the manufacture of polyesters and polyamides [6]. On the other hand, the co-product 9-octadecene can be dimerized and hydrogenated to give 10,11-dioctyleicosane, a lube-oil-range hydrocarbon intermediate [7]. 

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