THE OXIDATION OF CARBON-HYDROGEN BONDS USING OZONE
The present disclosure is directed to novel methods of oxidizing hydrocarbons, particularly terpenes, using ozone, compounds made according to said methods, and compositions comprising said compounds.
1 . A method of oxidizing hydrocarbon C—H bonds using ozone.
2 . A method of preparing an alcohol or carbonyl compound from an alkane using ozone, comprising the steps of (1) exposing the alkane to ozone, optionally in an aqueous and/or non-aqueous solvent, and (2) isolating or purifying the resulting alcohol or carbonyl product.
3 . The method of claim 2 , wherein the alkane is an alkane according to Formula I.
wherein R 1 is either Ra or C(Ra)(Ra)(Ra), and wherein each instance of Ra is independently selected from H, C1-20alkyl, aryl and heteroaryl, and wherein said C1-20alkyl, aryl and/or heteroaryl are each optionally independently substituted, as defined herein, for example, substituted with one or more C1-20alkyl, hydroxy, C1-20alkoxy, carboxy, halogen, cyano, acyl (C1-20alkylcarbonyl), C1-20alkoxycarbonyl, or C1-20alkylaminocarbonyl.
4 . The method according to claim 3 , wherein R 1 of the alkane is C(Ra)(Ra)(H), and the alkane is an alkane according to Formula II:
wherein Ra is independently selected from H, C1-20alkyl, aryl and heteroaryl, and
wherein said C1-20alkyl, aryl and/or heteroaryl are each optionally independently substituted, as defined herein, for example, substituted with one or more C1-20alkyl, hydroxy, C1-20alkoxy, carboxy, halogen, cyano, acyl (C1-20alkylcarbonyl), C1-20alkoxycarbonyl, or C1-20alkylaminocarbonyl.
5 . The method according to claim 4 , wherein the method further comprises the step (3) of exposing the alcohol of the formula to an acid to yield an alkene (e.g., via acid-catalyzed E2 elimination), and optionally isolating or purifying said alkene.
6 . The method according to claim 5 , wherein the method further comprises the step (4) of exposing the alkene from step (3) to ozone followed by oxidative and/or reductive decomposition to yield one or two carbonyl compounds.
7 . A method of preparing a carbonyl compound from an alkane, comprising the steps of (1) exposing the alkane to ozone to form an alcohol, (2) reacting the alcohol with an acid to yield an alkene, (3) exposing the resulting alkene to ozone to yield a secondary ozonide, (d) oxidatively or reductively decomposing the secondary ozonide to yield one or more carbonyl compounds, and (e) isolating or purifying one or more of said carbonyl compounds.
8 . The method according to claim 7 , wherein the alkane is an alkane according to Formula II:
wherein each instance of Ra is independently selected from H, C1-20alkyl, aryl and heteroaryl, and wherein said C1-20alkyl, aryl and/or heteroaryl are each optionally independently substituted, as defined herein, for example, substituted with one or more C1-20alkyl, hydroxy, C1-20alkoxy, carboxy, halogen, cyano, acyl (C1-20alkylcarbonyl), C1-20alkoxycarbonyl, or C1-20alkylaminocarbonyl.
9 . The method according to claim 1 , wherein step (1) occurs in aqueous and/or non-aqueous solvent.
10 . The method according to claim 9 , wherein the step (1) occurs in an alkaline aqueous solution or alkaline aqueous emulsion.
11 . The method according to claim 1 , wherein step (1) does not comprise the presence or addition of any catalyst.
12 . The method according to claim 1 , wherein in step (1) ozone is the only oxidizing agent present.
13 . The method according to claim 1 , wherein the alkane is a terpene or terpenoid, optionally, wherein the alkane is a fully saturated terpene or terpenoid.
14 . An alcohol or carbonyl compound prepared according to claim 1 .
15 . The alcohol or carbonyl compound according to claim 14 , wherein the alcohol or carbonyl compound is selected from the group consisting of:
16 . A flavor or fragrance composition comprising a compound according to claim 15 .