Cyclododecanone Compound

Production. The main industrial syntheses start from compounds produced from cyclododecatriene either by ring expansion of cyclododecanone or by depolymerization of polyesters of 15-hydroxypentadecanoic acid (from 1,12-dodecanediol). 

Sumimoto introduced a new sebacic acid process including several catalytic hydrogenation reactions.342 The synthesis starts with naphthalene, which is first partially hydrogenated to tetralin over cobalt oxide or molybdenum oxide, then to decalin over ruthenium or iridium on carbon. The selectivity to cw-decalin is better than 90%. In a later phase of the synthesis 5-cyclododecen-l-one is hydrogenated over Raney nickel to obtain a mixture of cyclododecanone and cyclodode-canol in a combined yield of 90%. The selectivity of this step is not crucial since subsequent oxidation of either compound leads to the endproduct sebacic acid. 

This ring expansion has been applied to the synthesis of the 15-membered ( )-muscone [37], First cyclododecanone was tranformed to cyclotridec-3-enone (V/67) in a five step synthesis [38]. The latter, treated with the Grignard reagent formed from prop-l-enyl bromide, generated a mixture of the isomeric compounds, V/68, in nearly 50 % yield. Obviously the methyl group sterically... 

Muscone and exaltone are important perfumery compounds with hard-to-make 15-membered ring structures. Cyclododecanone is commercially available addition of a fused five-mcmbered ring and fragmentation of the 12,5-ring system is a useful route to these 15-meinbered ring compounds. 

A suspension of 15.0 g (4.05 mol) of the reagent in 20 mL of freshly distilled benzene containing 0.250 g (1.36 mmol) of cyclododecanol is heated to 70 °C for 1.5 h. The solution is filtered through Celite (diatomaceous earth), the pellets are washed with 70 mL of benzene, and the combined filtrates are evaporated under reduced pressure to yield 0.226 g (90%) of cyclododecanone as colorless crystals, mp 56-59 °C. The pure compound melts at 59-61 °C. 

For some time now, brassylic acid has been obtained from cyclododecanone, which is reacted with dimethyl carbonate to give methyl 2-oxocyclododecylcarboxylate. Subsequent cleavage of the latter compound under strongly alkaline conditions leads to dimethyl brassylate [208a], Now, brassylic acid is also available from microbial oxidation of n-tridecane with Candida tropicaulis [124b]. 

Chromyl chloride can also produce ketones, but a common side reaction is formation of an a-chloro ketone, as in the conversion of cyclododecene to a-chlorocyclododecanone (401) in 79% yield. In a subsequent reaction, the chloride moiety in 401 was reduced to give cyclododecanone in 95% yield with zinc and acetic acid. Chromyl chloride also reacts with alkenes to give a trans-chlorohydrin rather than a carbonyl compound (see sec. 2.10.C for the preparation of chlorohydrins), as in the conversion of cyclohexene to tran5-2-chlorocyclohexanol. 5 It is interesting that in this particular case (the temperature was maintained at -78°C in dichloromethane), the cis-chlorohydrin was formed. ... 

Di-t-butyl chromate and its pyridine adduct are suitable for large-scale oxidations of alcohols to ketones, thus cyclododecanol was converted into cyclododecanone (97 Alcohols are easily separated from non-hydroxylic compounds via their calcium chloride complexes. This method was used to separate cyclododecanone and cyclododecanol and is suitable for the separation of large quantities of material." All-cis-cyclododecane-l,5,9-triol was converted into the all-cis-tri-amine by tosylation, azide substitution, and reduction, and the amine acylated with 2,3-dimethoxybenzoyl chloride to give the tri-amide, an analogue of enterochelin. ... 

Cyclic compounds continue to find use as chain extenders. 5-Methylcyclo-hexane-l,3-dione has been used for the synthesis of 3-methyl- and 3,6-di-methyl-tridecanoic ester, and the enamine synthesis, usually utilizing cyclopentanone or cyclohexanone, has been extended to the use of cyclo-decanone and cyclododecanone. Reaction occurs through a cyclobutanone... 

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