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

A method for synthesizing 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 comprising the steps of:

• (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;
• wherein time and temperature conditions for step (b) are such that the predominant product is 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.

A method for synthesizing 5-epi-β-vetivone 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;
• and
• (c) isolating the (−)-premnaspirodiene;
• (d) subjecting the isolated (−)-premnaspirodiene to oxidation of an allylic carbon to form (−)-solavetivone;
• and
• (e) subjecting the (−)-solavetivone formed in step (d) to acid-catalyzed isomerization to form 5-epi-β-vetivone;
• wherein time and temperature conditions for step (e) are such that the predominant product is 5-epi-β-vetivone.

A method for synthesizing 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 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;
• and
• (c) isolating the (−)-premnaspirodiene;
• (d) subjecting the isolated (−)-premnaspirodiene to oxidation of an allylic carbon to form (−)-solavetivone;
• and
• (e) subjecting the (−)-solavetivone formed in step (d) to acid-catalyzed isomerization to form the 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;
• wherein time and temperature conditions for step (e) are such that the predominant product is the 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.

A method for synthesizing 2-isopropyl-6,10-dimethyl-spiro[4.5]deca-2,6-dien-8-one 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;
• and
• (c) isolating the (−)-premnaspirodiene;
• (d) subjecting the isolated (−)-premnaspirodiene to oxidation of an allylic carbon to form (−)-solavetivone;
• and
• (e) subjecting the (−)-solavetivone formed in step (d) to acid-catalyzed isomerization to form 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;
• wherein time and temperature conditions for step (e) are such that the predominant product is the 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;
• and
• (f) isolating the 2-isopropyl-6,10-dimethyl-spiro[4.5]deca-2,6-dien-8-one from the 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 formed in step (e) by a method selected from the group consisting of thin-layer chromatography, column chromatography, gas chromatography, and countercurrent distribution.

A method for synthesizing 2-isopropyl-6,10-dimethyl-spiro[4.5]deca-1,6-dien-8-one 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;
• and
• (c) isolating the (−)-premnaspirodiene;
• (d) subjecting the isolated (−)-premnaspirodiene to oxidation of an allylic carbon to form (−)-solavetivone;
• and
• (e) subjecting the (−)-solavetivone formed in step (d) to acid-catalyzed isomerization to form 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;
• wherein time and temperature conditions for step (e) are such that the predominant product is the 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;
• and
• (f) isolating the 2-isopropyl-6,10-dimethyl-spiro[4.5]deca-1,6-dien-8-one from the 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 formed in step (e) by a method selected from the group consisting of thin-layer chromatography, column chromatography, gas chromatography, and countercurrent distribution.