Fragrance and methods for production of 5-epi-β-vetivone, 2-isopropyl-6, 10-dimethyl-spiro[4.5]deca-2,6-dien-8-one, and 2-isopropyl-6, 10-dimethyl-spiro[4.5]deca-1, 6-dien-8-one

1. A substantially purified compound having the structure

2. A composition, comprising a compound having the structure

wherein:

the compound of Formula (1) is the predominant product in the composition; and

the composition is produced by a method comprising:

(a) subjecting (−)-premnaspirodiene to oxidation of an allylic carbon to form (−)-solavetivone; and

(b) subjecting the (−)-solavetivone formed in step (a) to acid-catalyzed isomerization to form a compound having the structure of Formula (1), wherein time and temperature conditions for step (b) are such that the predominant product is a compound having the structure of Formula (1), thereby producing the composition comprising the compound of Formula (1) as the predominant product.

3. A fragrance composition, comprising a mixture of 2-isopropyl-6,10-dimethyl-spiro[4.5]deca-2,6-dien-8-one and 2-isopropyl-6,10-dimethyl-spiro[4.5]deca-1,6-dien-8-one in an amount effective to impart a fragrance.

4. A fragrance composition, comprising the compound 2-isopropyl-6,10-dimethyl-spiro[4.5]deca-1,6-dien-8-one, wherein the composition is substantially free of 2-isopropyl-6,10-dimethyl-spiro[4.5]deca-2,6-dien-8-one.

5. A fragrance composition, comprising the compound 2-isopropyl-6,10-dimethyl-spiro[4.5]deca-2,6-dien-8-one, wherein the composition is substantially free of 2-isopropyl-6,10-dimethyl-spiro[4.5]deca-1,6-dien-8-one.

6. A method for producing (−)-premnaspirodiene from a terpene substrate, comprising the steps of:

(a) providing a terpene substrate to a host cell transformed or transfected with a vector comprising a sequence encoding a Hyoscyamus muticus premnaspirodiene synthase gene;

(b) culturing the host cell under conditions suitable to produce (−)-premnaspirodiene from the terpene substrate, wherein the (−)-premnaspirodiene is sequestered during the culturing step; and

(c) isolating the (−)-premnaspirodiene.

7. The method of claim 6 , wherein the step of providing the terpene substrate is performed by synthesizing the terpene substrate in the host cell.

8. The method of claim 7 , wherein the terpene substrate is farnesyl diphosphate.

9. The method of claim 6 , wherein the host cell is a eukaryotic cell.

10. The method of claim 9 , wherein the host cell is a yeast cell.

11. The method of claim 10 , wherein the host cell is a Saccharomyces cerevisiae cell.

12. The method of claim 6 , wherein:

the (−)-premnaspirodiene is sequestered by binding it to a hydrophobic resin; and

the (−)-premnaspirodiene is isolated from the hydrophobic resin.

13. The method of claim 6 , wherein:

the (−)-premnaspirodiene is sequestered in a non-polar solvent phase of a two-phase system during fermentation;

the non-polar solvent phase is substantially immiscible with an aqueous phase; and

the (−)-premnaspirodiene is removed from the non-polar solvent phase by distillation.

14. The method of claim 13 , wherein the non-polar solvent phase is a high-molecular weight aliphatic hydrocarbon selected from among a straight-chain or branched-chain isomer of dodecane, tridecane, tetradecane, pentadecane, and hexadecane wherein the high-molecular weight aliphatic hydrocarbon is optionally substituted with one or more hydroxy or halogen substituents such that the substituted hydrocarbon is substantially immiscible with the aqueous phase.

15. A composition, comprising the compound:

which is the predominant product in the composition.

16. An enantiomerically pure compound having the structure

17. A composition, comprising the compound of claim 16 , wherein the composition is free of the enantiomer of the compound of Formula (1).

18. A composition, comprising the compound of claim 16 , wherein the composition is free of beta-vetivone.