16409-43-1

Basic information

• Product Name: FEMA 3236
• Synonyms: (Z)-Rose oxide;2-(2-methyl-1-propenyl)-4-methyltetrahydro-pyra;2H-Pyran, tetrahydro-4-methyl-2-(2-methyl-1-propenyl)-;2H-Pyran, tetrahydro-4-methyl-2-(2-methylpropenyl)-;4-Methyl-2-(2-methyl-1-propenyl)tetrahydro-2H-pyran;c-rose oxide;Pyran, 2-(2-methyl-1-propenyl)-4-methyltetrahydro-;Pyran, tetrahydro-2-(2-methyl-1-propenyl)-4-methyl-
• CAS NO: 16409-43-1
• Molecular Formula: C₁₀H₁₈O
• Molecular Weight: 154.25
• EINECS: 240-457-5
• Mol File: 16409-43-1.mol

Chemical Properties

• Boiling Point: 86 °C20 mm Hg(lit.)
• Flash Point: 157 °F
• Appearance: /
• Density: 0.873 g/mL at 20 °C(lit.)
• Vapor Pressure: 0.551mmHg at 25°C
• Refractive Index: n20/D 1.454
• Storage Temp.: under inert gas (nitrogen or Argon) at 2-8°C
• Water Solubility: 920mg/L at 20℃
• BRN: 1680588
• CAS DataBase Reference: FEMA 3236(CAS DataBase Reference)
• NIST Chemistry Reference: FEMA 3236(16409-43-1)
• EPA Substance Registry System: FEMA 3236(16409-43-1)

Safety Data

• Hazard Codes: Xi
• Statements: 38-36/37/38
• Safety Statements: 36-26
• WGK Germany: 3
• RTECS: UQ1470000
• F: 10-23
• Hazardous Substances Data: 16409-43-1(Hazardous Substances Data)

Usage

Uses

Used in Flavor and Fragrance Industry:
FEMA 3236 is used as a flavoring agent for its green, vegetative, and herbal taste with a citrus nuance at 20 ppm. It is also used as a fragrance ingredient to provide a distinctive geranium top note to various perfumes and scented products.
Used in Essential Oils:
FEMA 3236 is used in essential oils such as Bulgarian rose oil and geranium oil, where it occurs in small quantities. It contributes to the overall aroma and scent profile of these essential oils.
Used in Food and Beverage Industry:
FEMA 3236 can be used as a flavoring agent in the food and beverage industry to impart a unique taste and aroma to various products. Its green, vegetative, and herbal taste with a citrus nuance can be used to enhance the flavor of beverages, confectionery, and other food products.
Used in Cosmetics and Personal Care Products:
FEMA 3236 can be used in cosmetics and personal care products as a fragrance ingredient to provide a distinctive geranium and rose oil scent. It can be incorporated into products such as perfumes, body lotions, and shower gels to enhance their sensory properties.

Preparation

Rose oxide is usually prepared from citronellol, which can be converted into a mixture of two allyl hydroperoxides by photosensitized oxidationwith singlet oxygen. Reduction of the hydroperoxideswith sodium sulfite yields the corresponding diols . Treatmentwith dilute sulfuric acid results in allylic rearrangement and spontaneous cyclization of one of the isomers; amixture of diastereoisomeric rose oxides is thus formed. The unreacted diol isomer is separated by distillation. (?)- Citronellol as the starting material yields an approximately 7 : 3 mixture of (?)-cisand (?)-trans-rose oxide. Higher proportions of the cis-isomer may be obtained by dehydration with a stronger acid.Other methods for the production of rose oxide starting from citronellol consist of halogenation–dehalogenation reactions of citronellol.An alternative technical process does not use citronellol but starts from prenal [107-86-8] and 3-methyl-3-buten-1-ol [763-32-6]. Under acidic conditions, the reaction affords a mixture of isomers of dehydro rose oxide (C10H16O6; [1786- 08-9], [92356-05-3], [60857-05-8]). Subsequent hydrogenation using a ruthenium/alumina catalyst leads to rose oxide.The proportion of cis-isomer can be increased by isomerization under acidic conditions.

Flammability and Explosibility

Nonflammable

InChI:InChI=1/C10H18O/c1-8(2)6-10-7-9(3)4-5-11-10/h6,9-10H,4-5,7H2,1-3H3

Synthetic route

(+/-)-(E)-2-methoxy-2,6-dimethyl-3-octen-8-ol (868552-84-5) → rose oxide (16409-43-1)

Conditions	Yield
With boron trifluoride diethyl etherate In dichloromethane Ambient temperature;	94%

2-(2,4-Dichlorphenoxy)-3,4,5,6-tetrahydro-4-methyl-2H-pyran (57745-77-4) + 2-methylpropen-1-ylmagnesium bromide (38614-36-7) → rose oxide (16409-43-1)

Conditions	Yield
In benzene for 0.5h; Ambient temperature;	86%

Acetic acid 6-chloro-3,7-dimethyl-oct-7-enyl ester (74514-34-4) → rose oxide (16409-43-1)

Conditions	Yield
With sodium hydroxide; sulfuric acid 1.) heating; Yield given. Multistep reaction;

8-hydroxy-2,6-dimethyl-2-octen-4-one (81925-87-3) → rose oxide (16409-43-1)

Conditions	Yield
With potassium hydrogensulfate; lithium aluminium tetrahydride 1) Et2O 2) heating; Yield given. Multistep reaction;

6-chloro-3,7-dimethylocta-7-en-1-ol (17690-32-3, 27463-30-5) → rose oxide (16409-43-1)

Conditions	Yield
With sodium hydroxide; sulfuric acid 1.) heating; Yield given. Multistep reaction;

3,7-dimethyl-4,7-octadienol (37828-36-7) → rose oxide (16409-43-1) + iso-rose oxide (35598-65-3)

Conditions	Yield
With iodine In tetrachloromethane for 2h; Heating; Yield given. Yields of byproduct given;

Citronellol (106-22-9) → rose oxide (16409-43-1) + 3,7-dimethyl-oct-6-enal (106-23-0, 26489-02-1) + isopulegone (29606-79-9) + Isopulegol (89-79-2)

Conditions	Yield
With CrO3/silica gel In various solvent(s) at 40℃; under 165013 Torr; for 4h;

(E)-2-methyl-1,5-heptadien-4-ol (107791-76-4) → rose oxide (16409-43-1)

Conditions	Yield
Multi-step reaction with 3 steps 1: 58 percent / mercury(II) acetate / 1.) reflux, 24 h, 2.) 2 days 2: 94 percent / sodium borohydride / ethanol 3: iodine / CCl4 / 2 h / Heating View Scheme
Multi-step reaction with 3 steps 1: 69 percent / propionic acid / Heating 2: 78.5 percent / lithium aluminium hydride / diethyl ether / 3 h / Heating 3: iodine / CCl4 / 2 h / Heating View Scheme

3,7-dimethyl-4,7-octadienal (29414-60-6) → rose oxide (16409-43-1)

Conditions	Yield
Multi-step reaction with 2 steps 1: 94 percent / sodium borohydride / ethanol 2: iodine / CCl4 / 2 h / Heating View Scheme

ethyl 3,7-dimethyl-4,7-octadienoate (86000-34-2) → rose oxide (16409-43-1)

Conditions	Yield
Multi-step reaction with 2 steps 1: 78.5 percent / lithium aluminium hydride / diethyl ether / 3 h / Heating 2: iodine / CCl4 / 2 h / Heating View Scheme

Citronellol (106-22-9) → rose oxide (16409-43-1)

Conditions	Yield
Multi-step reaction with 2 steps 1: HOCl / CH2Cl2 2: 1.) NaOH; 2.) H2SO4 / 1.) heating View Scheme
Multi-step reaction with 2 steps 1: 89 percent / (PhSe)2, Et4NBr / electrolysis 2: 94 percent / BF-etherate / CH2Cl2 / Ambient temperature View Scheme
With rose bengal; sodium sulfite In methanol at 70℃; for 3h; Irradiation;
Stage #1: Citronellol With oxygen; tetrakis(pentafluorophenyl)porphyrin In carbon dioxide; dimethyl carbonate under 135014 Torr; for 4h; Supercritical conditions; Irradiation; Stage #2: With sodium sulfite In dimethyl carbonate; water Stage #3: With hydrogenchloride In dimethyl carbonate; water

4-methyl-tetrahydro-pyran-2-one (1121-84-2) → rose oxide (16409-43-1)

Conditions	Yield
Multi-step reaction with 3 steps 1: 92 percent / Mg / tetrahydrofuran 2: 1) potassium tert-butoxide 2) HCl aq. / 1) DMF, 40 deg C 2) THF 3: 1) LiAlH4 2) KHSO4 / 1) Et2O 2) heating View Scheme

3,7-dimethyl-5-(2'-methyl-2'-propenyl)-7-octen-1,5-diol (81925-86-2) → rose oxide (16409-43-1)

Conditions	Yield
Multi-step reaction with 2 steps 1: 1) potassium tert-butoxide 2) HCl aq. / 1) DMF, 40 deg C 2) THF 2: 1) LiAlH4 2) KHSO4 / 1) Et2O 2) heating View Scheme

C11H22O2 (608100-92-1) → rose oxide (16409-43-1)

Conditions	Yield
With hydrogenchloride In hexane at 0℃; for 3h;	1.263 g

4-methylidene-2-(2-methylprop-1-enyl)tetrahydro-2H-pyran (60857-05-8) → rose oxide (16409-43-1)

Conditions	Yield
With hydrogen at 70℃; under 3000.3 Torr; for 4h; Reagent/catalyst; Time; Autoclave;

Citronellol (106-22-9) → rose oxide (16409-43-1) + 2,6-Dimethyl-3,8-diacetoxy-1-octen (23062-49-9) + C12H22O3 + C16H26O6

Conditions	Yield
With oxygen; palladium diacetate; p-benzoquinone In acetic acid at 80℃; under 3800.26 Torr; for 7h; Catalytic behavior; Time; Pressure; regioselective reaction;

Citronellol (106-22-9) → rose oxide (16409-43-1) + 2,6-Dimethyl-3,8-diacetoxy-1-octen (23062-49-9) + C12H22O3

Conditions	Yield
With oxygen; palladium diacetate; p-benzoquinone In acetic acid at 80℃; under 760.051 Torr; for 3h; Catalytic behavior; regioselective reaction;

Citronellol (106-22-9) → rose oxide (16409-43-1) + 2,6-Dimethyl-3,8-diacetoxy-1-octen (23062-49-9) + C16H26O6

Conditions	Yield
With oxygen; palladium diacetate; p-benzoquinone In acetic acid at 80℃; under 7600.51 Torr; for 9h; Catalytic behavior; Time; Pressure; Temperature; regioselective reaction;

rose oxide (16409-43-1) → 2-isobutyl-4-methyl-tetrahydro-pyran (13477-62-8)

Conditions	Yield
With palladium on carbon; hydrogen; C64H118O20 In water at 20℃; for 2h; Reagent/catalyst;	100%

rose oxide (16409-43-1) → 4-methyltetrahydro-2H-pyran-2-carbaldehyde

Conditions	Yield
Stage #1: rose oxide With ozone In methanol at -70℃; for 3h; Stage #2: With oxygen In methanol Stage #3: With triethyl phosphite In methanol at -20 - 0℃; for 2h;	55%

rose oxide (16409-43-1) + [1,4]naphthoquinone (130-15-4) → 2-(2-methyl-1-(4-methyltetrahydro-2H-pyran-2-yl)propan-2-yl)naphthalene-1,4-dione

Conditions	Yield
With Iron(III) nitrate nonahydrate; sodium tetrahydroborate In ethanol; acetonitrile at 20℃; for 0.5h;	30%

rose oxide (16409-43-1) → 2-(1-fluoro-2-methylallyl)-4-methyltetrahydropyran

Conditions	Yield
With Selectfluor In water; acetonitrile at 75℃; for 4h; Ene Reaction;	20%

rose oxide (16409-43-1) + Trichloroacetyl chloride (76-02-8) → 2,2-Dichloro-3,3,7-trimethyl-(E)-4-nonen-9-olide (84473-51-8) + 2,2-Dichloro-3,3-dimethyl-4-(4-methyl-tetrahydro-pyran-2-yl)-cyclobutanone (84473-52-9)

Conditions	Yield
With zinc; trichlorophosphate In diethyl ether at 30℃; for 3h; Yield given. Yields of byproduct given;
With zinc; trichlorophosphate In diethyl ether at 30℃; for 3h; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

rose oxide (16409-43-1) + p-nitrobenzenesulfonamide (6325-93-5) → C16H22N2O5S + C16H22N2O5S

Conditions	Yield
With [bis(acetoxy)iodo]benzene; 1,3-dimethyl-imidazoline-2-selone In dichloromethane Inert atmosphere; Overall yield = 60 percent; Overall yield = 106 mg; diastereoselective reaction;

Upstream product

• 57745-77-4 2-(2,4-Dichlorphenoxy)-3,4,5,6-tetrahydro-4-methyl-2H-pyran 
• 38614-36-7 2-methylpropen-1-ylmagnesium bromide 
• 81925-87-3 8-hydroxy-2,6-dimethyl-2-octen-4-one 
• 17690-32-3 6-chloro-3,7-dimethylocta-7-en-1-ol 
• 37828-36-7 3,7-dimethyl-4,7-octadienol 
• 106-22-9 Citronellol 
• 29414-60-6 3,7-dimethyl-4,7-octadienal 
• 86000-34-2 ethyl 3,7-dimethyl-4,7-octadienoate 
• 1121-84-2 4-methyl-tetrahydro-pyran-2-one 
• 81925-86-2 3,7-dimethyl-5-(2'-methyl-2'-propenyl)-7-octen-1,5-diol 
• 608100-92-1 C₁₁H₂₂O₂ 
• 60857-05-8 4-methylidene-2-(2-methylprop-1-enyl)tetrahydro-2H-pyran 
• 16122-01-3 3,7-Dimethyl-6-octene-1,5-diol 
• 107-86-8 3,3-dimethyl acrylaldehyde 

Downstream Products

• 13477-62-8 2-isobutyl-4-methyl-tetrahydro-pyran 

Relevant articles and documents

173. β-Cleavage of Bis(homoallylic) Potassium Alkoxides. Preparation of 3-Hydroxypropyl and 4-Hydroxybutyl Propenyl Ketones from γ- and δ-Lactones. Synthesis of (+/-)-Rose Oxide

Starting from γ- and δ-lactones 1-3, a two-step preparation of 3-hydroxypropyl and 4-hydroxybutyl propenyl ketones 10-18 is described, involving as the key step the β-cleavage of the bis(homoallylic) potassium alkoxides 4a-9a.This novel methodology is illustrated by a short synthesis of (+/-)-rose oxide (20).

Palladium catalyzed oxidation of biorenewable β-citronellol and geraniol for the synthesis of polyfunctionalized fragrances

β-Citronellol and geraniol are bio-renewable compounds found in essential oils of various plants. Allylic oxidation of trisubstituted sterically highly encumbered carbon-carbon double bonds in their molecules with dioxygen can be efficiently catalyzed by the palladium acetate/p-benzoquinone combination under 5?10 atm of dioxygen pressure without the need for conventionally used metal co-catalysts. Both substrates gave allyl acetates in ca. 90% combined yield. The oxidation of geraniol proceeded with excellent site-selectivity involving only one of its two C[dbnd]C bonds. Geraniol gave both linear and branched allyl acetates in comparable yields, whereas the reaction of β-citronellol showed high regioselectivity for the corresponding branched product. Polyfunctionalized oxygenated terpenes produced from β-citronellol and geraniol are of a potential importance as ingredients for fragrance compositions.

PROCESS FOR THE PREPARATION OF CIS-ROSE OXIDE

The present invention relates to a process for the preparation of a composition enriched in cis-2-(2-methylprop-1-enyl)-4-methyltetrahydropyran, comprising the catalytic hydrogenation of 2-(2-methylprop-1-enyl)-4-methylenetetrahydropyran in the presence of hydrogen and a heterogeneous catalyst comprising ruthenium.

Aluminium triflate catalysed cyclisation of unsaturated alcohols: novel synthesis of rose oxide and analogues

Aluminium trifluoromethanesulfonate was used as an efficient catalyst for the cycloisomerisation of several unsaturated alcohols into cyclic ethers such as rose oxide and some of its ether analogues.

Comparative study of the vicinal functionalization of olefins with 2:1 bromide/bromate and iodide/iodate reagents

A comparative evaluation was made on the syntheses of vicinal halohydrins, halo methyl ethers, and halo acetates from olefins using 2:1 Br-/BrO3- and I-/IO3- reagents. In many cases both reagents afforded products selectively in high yields. The highest halogen atom efficiencies attained were 97% and 93% for Br-/BrO3- and I-/IO3-, respectively. Of the two reagents, I-/IO3- was established to be the preferred reagent for vicinal functionalization of linear alkenes and also for halo acetate preparation. However, only Br-/BrO3- was effective for vicinal functionalization of trans-stilbene and chalcones.

Oxidation of alcohols to carbonyl compounds with CrO3· SiO2 in supercritical carbon dioxide

Supercritical carbon dioxide (scCO2) is an effective reaction medium to perform the oxidation of primary and secondary aliphatic alcohols to the corresponding carbonyl compounds with chromium trioxide supported on silica. These reactions were performed by flowing a solution of the alcohol in scCO2 through a column containing the supported reagent and recovering the product by depressurization. This method avoids the use of organic solvents and the contamination of the products with chromium species.

Photochemical and thermochemical solar syntheses using flat-bed solar collectors/solar reactors

The invention relates to a method for carrying out photochemical and thermochemical solar syntheses by means of flat-bed solar light collectors without devices for focusing the sunlight. The method is particularly well suited for producing flavors, aromas and complex thereof. The flat-bed solar light collector is suitable especially for producing steroids and derivatives thereof. It can further be used for the photooxidation (photooxygenation) of terpene olefins and therefore for the synthesis of fragrants such as rose oxide, myrtenol and myrtenal which are of industrial interest. The solar collector is also suitable for photochemical addition reactions and rearrangements.

Process for producing a rose oxide

An improved process for production of an isomer mixture of Z- and E-2-?2-Methyl-prop-1-en-1-yl-!-4-methyl-tetrahydropyran, more commonly known under the name cis- and trans-rose oxide, which as a rule contains at least 80% of the natural Z-isomers (cis-rose oxide) which are valuable in the perfume industry.

SYNTHESES OF TETRAHYDROPYRANS BY PPh3/CBr4 INDUCED CYCLIZATION OF ACETALS : APPLICATION TO A SYNTESIS OF ROSE OXIDE

Substituted tetrahydropyrans are prepared in good yields by PPh3/CBr4 induced cyclization of acetals.The utility of this new procedure is illustrated by the synthesis of cis-2-(methyl-1 propenyl)-4 methyltetrahydropyran (rose oxide).