Acorone

Suggest a synthesis for spiroketone (8), an inter- lediate in a synthesis of acorone. 

Aconitum coreanum Acorone Accoridine Corypidine Coryphine Tangutisine... 

R-pulegone (59) to y-acoradiene (63), 5-acoradiene (65), and the enantiomers (67) and (68) of acorone and isoacorone have been described (Scheme 12).33 An interesting feature of the synthetic sequence is the use of stannic chloride to improve... 

Additional stereoselective syntheses of acorone (147) and isoacorone (148) have been recorded (Scheme 26). ... 

Alternatively, trialkylstannylcesium compounds can be prepared by fluoride ion-induced desilylation. Treatment of (trimethysilyl)tributylstannane with cesium fluoride affords a tributylstanyl anion. The anion reacts with a C-I bond to form a vinyl anion that promotes intramolecular cyclization [6]. The spiro ketone obtained is converted into a natural sesquiterpene acorone (Scheme 2.3). 

Two acorones or giant boas open their mouths to let the animals and yakurunas used by vegetalistas give their farewells to the great sumiruna. White mermaids make the capsule levitate. Flying saucers hurry to receive it, and to accompany it in its astral travel. 

It is clear from these and previous results obtained over the past two or three years that the spiro-sesquiterpenes provide an important link between certain monocyclic and tricyclic sesquiterpenes. This is further exemplified by the recent work of Andersen and SyrdaP who have now reappraised the absolute stereochemistries of (-)-a- (137) and (- )-/3-alaskene (138). It now appears that 5-acoradiene, isolated by Hirose et is, in fact, (-I-)- -alaskene. Andersen and Syrdal also made the interesting observation that phthalic anhydride dehydration of the diols derived from iso-acorone (139) gave rise to small amounts of (-f )-a-cedrene (126 R = Me) and (— )-2-epi-a-cedrene (136). Subsequently these authors found that (-t- )-nerolidol (140) and a number of its derivatives undergo acid-catalysed cyclization to a mixture of a- and -bisabolenes (141), of which the... 

Finder et have reported an attempted synthesis of acorone (150) using as the key step to the spiro-system the intramolecular Michael reaction of the diketo-ester (151). An almost identical sequence, however, was reported eight years ago by Mellor and Munavalli in the form of a personal communication All attempts by Finder and co-workers to effect isopropylation of the resultant spiro diketo-ester (152) met with failure. ... 

Acorone (166), a sesquiterpene diketone isolated from the essential oil of roots of Acorus calamus, was the first spirosesquiterpenoid to be characterized, with the carbon skeleton of cation 158. At present several compounds of this class are known and an extensive review has been published (267). Hydrocarbons (e.g., y-acoradiene = a-alaskene, 167) and alcohols (e.g., a-acorenol, 168) directly derivable from the spiro-cation 159 have been isolated from wood of Juniperus... 

C2iH280sr Dihydrodesacetoxyglaucolide-A, 40B, 514 C2iHjsBrNjOaS, Acorone p-bromophenylsulphonylhydrazone, 31B, 216 C2iH2sBr03S, a-Caryophyllene alcohol p-bromobenzenesulphonate, 35B, 386... 

Marx JN, Norman LR. Synthesis of (—)-acorone and related spirocyclic sesquiterpenes. J. Org. Chem. 1975 40 1602-1606. 

The Absolute Stereochemistry of the Alaskenes and Acorone-related Sesqui-... 

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