Exaltone

The use of macrocyclic compounds of the thiophene series for the preparation of macrocyclic alicyclie ketones has been mentioned earlier. " A new synthesis of exaltone has been carried out using (136) as the starting material. ... 

Macrocyclic ketones. This reagent has been used for cycloolefination of acetylenic dialdehydes (Wittig-Horner reaction) as a route to muscone, exaltone, and civetone. A synthesis of the last ketone (3) is formulated (equation 1). 

In the synthesis of the following lactones, the oxygen atom has been introduced by Baeyer-Villiger rearrangement, e.g. ( )-phoracantholide I [137], ( )-lactone antibiotic A26771B [138], exaltone [139]. 

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. 

One step in a synthesis of d/-muscone (4) from exaltone (1) involved dehydiobromina-tion of (2). This was effected with l,5-diazabicyclo[4.3.0]noncne-5 in 70% yield. Treatment with pota.s.sium /-butoxide in t-butanol or DMSO afforded only the dioxine (5). ... 

The Smh-mediated intramolecular Barbier procedure has been applied to several diverse systems, and in each case has been determined to be superior to other protocols. Suginome and Yamada applied the technique to syntheses of exaltone and ( )-muscone (equation 40). Surprisingly, cyclization in this case generates a single diastereomer. It is claimed that the Smh procedure provides better yields than procedures incorporating Mg/HgCh or n-butyllithium. 

Exaltone (cyclopentadecanone) (118 Scheme 39) and more so muscone (3-methylcyclopentadeca-none) (119) are valuable musk fragrances of great commercial potential. Since the construction of a 15-membered ring by direct ring closure is quite difficult, ring extension methods possess particular... 

Eschenmoser, A., Eelix, D., Ohioff, G. New fragmentation reaction of a,P-unsaturated carbonyls. Synthesis of exaltone and rac-muscone from cyclododecanone. Helv. Chim. Acta 1967, 50, 708-713. 

Eehr, C., Ohioff, G., Buchi, G. A new a,P-enone -> alkynone fragmentation. Synthesis of Exaltone and ( )-muscone. Helv. Chim. Acta 1979, 62, 2655-2660. 

Takahashi and coworkers have employed intramolecular reactions of anions of unsaturated protected cyanohydrins to produce unsaturated carbocyclic systems containing 10-, 14- and 16-membered rings which are convertible into natural products. These reactions occur regiospecifically at the a-position and usually do not involve ( ) — ( isomerization of P,7-double bonds. The preparation of 2-cyclopen-tadecenone (155), which is convertible into the macrocyclic perfumes muscone and exaltone, is illustrative of this methodology (Scheme 76). 

Ethyl nitroacetate-Dicthyl azodicarboxyl-ate-Triphcnylphosphine, 182 Ethyl 2-phenylsulfinyIacetate, 183 Ethyl vinyl ether, 184 d-Ethynyl-0-propiolactone, 283 Ethynyl p-tolyl sulfone, 183 Ethynyltrimethylsilane, 177 Evodone, 231,232,279 Exaltone, 35... 

Subliming Exaltone is better than crystallising it from aqueous EtOH for purification. The semicarbazone has m 186-187°. [Stevens Erickson J Am Chem Soc 64 146 1942, Mathur et al. J Chem Soc 3505 1963, Biens Hess Helv Chim Acta 71 1704 1988, Beilstein 7 III 203, 7 IV 118.]... 

AI3-38746 Cyclopentadecanone, 3-methyl- EINECS 208-795-8 FEMA No. 3434 HSDB 1219 3-Methyl-1-cyclopentadecanone 3-Methylcyclopentadecanone 3-Methylcyclopentadecan-1-one 3-Methylcydopenta-decanone, dl- 5-Methyl-1-cyclopentadecanone Methyl-exaltone Moschus ketone Muscone Muskone. Odiferous secretion of the musk. No longer used in perfumery. Liquid bp = 328 bpo.5 = 130 [a]6 = -13° insoluble in H2O, very soluble in EtOH, Et20, Me2CO. 

---