497-03-0

Basic information

• Product Name: TRANS-2-METHYL-2-BUTENAL
• Synonyms: (2E)-2-Methyl-2-butenal;(E)-2-Methyl-2-butenal;(E)-2-methylbut-2-en-1-al;(E)-2-methylbut-2-enal;2,2-Dimethylacrolein;2-Butenal,2-methyl-,(2E)-;2-Butenal,2-methyl-,(E)-;2-methyl-(E)-2-butenal
• CAS NO: 497-03-0
• Molecular Formula: C₅H₈O
• Molecular Weight: 84.12
• EINECS: 207-833-0
• Mol File: 497-03-0.mol
• Article Data: 20

Chemical Properties

• Melting Point: -101.15°C (estimate)
• Boiling Point: 116-119 °C752 mm Hg(lit.)
• Flash Point: 65 °F
• Appearance: Clear colorless to yellow/Liquid
• Density: 0.871 g/mL at 25 °C(lit.)
• Refractive Index: n20/D 1.448(lit.)
• Storage Temp.: Flammables area
• Water Solubility: Soluble in water
• Sensitive: Air Sensitive
• BRN: 1698207
• CAS DataBase Reference: TRANS-2-METHYL-2-BUTENAL(CAS DataBase Reference)
• NIST Chemistry Reference: TRANS-2-METHYL-2-BUTENAL(497-03-0)
• EPA Substance Registry System: TRANS-2-METHYL-2-BUTENAL(497-03-0)

Safety Data

• Hazard Codes: F,Xi
• Statements: 11-36/37/38-10
• Safety Statements: 16-26-36
• RIDADR: UN 1989 3/PG 2
• WGK Germany: 3
• TSCA: Yes
• HazardClass: 3
• PackingGroup: II
• Hazardous Substances Data: 497-03-0(Hazardous Substances Data)

Usage

Description

TRANS-2-METHYL-2-BUTENAL, also known as tiglic aldehyde, is a clear colorless to yellow liquid with a penetrating, powerful green ethereal odor. It is one of the major volatile constituents found in coriander and olive oil and can be prepared by the condensation of acetaldehyde and propionaldehyde.

Uses

Used in Chemical Synthesis:
TRANS-2-METHYL-2-BUTENAL is used as a starting reagent in the synthesis of various compounds, such as alkyl-branched tetraene hydrocarbons, pheromone components for dried fruit beetles, and volatile constituents of defensive secretions in certain insects.
Used in Fragrance Industry:
TRANS-2-METHYL-2-BUTENAL is used as a fragrance ingredient due to its powerful green ethereal odor, contributing to the characteristic scent of coriander and olive oil.
Used in Pharmaceutical Industry:
TRANS-2-METHYL-2-BUTENAL was used in the concise total synthesis of 7-demethylpiericidin A1, indicating its potential application in the development of pharmaceutical compounds.
Used in Insect Pheromones:
TRANS-2-METHYL-2-BUTENAL is used as a pheromone component for dried fruit beetles, playing a role in attracting and communicating between these insects.
Used in Defensive Secretions of Insects:
TRANS-2-METHYL-2-BUTENAL is a volatile constituent found in the defensive secretions of Leiobunum nigripalpi, an insect species, where it may serve as a protective mechanism against predators.

InChI:InChI=1/C5H8O/c1-3-5(2)4-6/h3-4H,1-2H3/b5-3+

Synthetic route

(E)-2-methyl-2-buten-1-ol (497-02-9) → 2-methylbut-2-enal (497-03-0)

Conditions	Yield
With dipyridinium dichromate In dichloromethane Inert atmosphere; Molecular sieve;	95%

dimethylacetylene (503-17-3) + carbon monoxide (201230-82-2) → 2-methylbut-2-enal (497-03-0)

Conditions	Yield
With C34H51NP2; hydrogen; palladium(II) acetylacetonate; toluene-4-sulfonic acid In tetrahydrofuran at 100℃; under 30003 Torr; for 10h; Schlenk technique; Autoclave; Inert atmosphere; stereoselective reaction;	87%
With acetylacetonatodicarbonylrhodium(l); C21H10F12NOP; hydrogen In toluene at 55℃; under 3750.38 Torr; for 20h; stereoselective reaction;	78%

Tiglic acid (80-59-1) → 2-methylbut-2-enal (497-03-0)

Conditions	Yield
With borane-THF In tetrahydrofuran at 0℃; for 2h;	81%
With Bis(N-methylpiperazinyl) aluminum hydride In tetrahydrofuran for 6h; Heating;	72%

2-methyl-3-ethoxybutanal (64197-53-1) → 2-methylbut-2-enal (497-03-0)

Conditions	Yield
With dichloro bis(acetonitrile) palladium(II) In dichloromethane for 36h; Ambient temperature;	80%
With toluene-4-sulfonic acid at 180℃;

isoprene epoxide (1838-94-4) → 2,5-dihydro-3-methyl-furan (1708-31-2) + 2-methylbut-2-enal (497-03-0)

Conditions	Yield
tetra-n-heptylammonium iodide; tributyltin iodide In para-xylene at 119℃; for 2h; Heating / reflux;	A 40.8% B 9.2%

carbon monoxide (201230-82-2) + isoprene epoxide (1838-94-4) → 5-methyl-3,6-dihydro-pyran-2-one (60920-98-1) + 2-methylbut-2-enal (497-03-0) + isoprene (78-79-5)

Conditions	Yield
With dicobalt octacarbonyl at 85℃; under 150012 Torr;	A 37% B 13% C 19%

isoprene epoxide (1838-94-4) → 2-methylbut-2-enal (497-03-0)

Conditions	Yield
HRh(PPh3)4 In benzene at 105℃; for 3h;	35%
rhodium hydrido (PEt3)3 complex In benzene at 105℃; for 3h; sealed tube;	35%

(2S,4S)-carveol (7632-16-8) + (+)-trans-carveol (2102-58-1) → 2-methylbut-2-enal (497-03-0) + butene-2 (107-01-7) + acetaldehyde (75-07-0) + isoprene (78-79-5)

Conditions	Yield
at 560℃; under 170 Torr;

acetaldehyde (75-07-0) + propionaldehyde (123-38-6) → 2-methylbut-2-enal (497-03-0)

Dichloromethyl methyl ether (4885-02-3) + 1-methylprop-1-enyltributyltin (86633-14-9, 86633-15-0, 859828-60-7) → 2-methylbut-2-enal (497-03-0) + (Z)-2-methyl-2-butenal (6038-09-1)

Conditions	Yield
With aluminium trichloride In dichloromethane at -78℃; for 4h; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

Dichloromethyl methyl ether (4885-02-3) + dibutylbis(1-methyl-1-propenyl)stannane → 2-methylbut-2-enal (497-03-0) + (Z)-2-methyl-2-butenal (6038-09-1)

Conditions	Yield
With aluminium trichloride In dichloromethane at -78℃; for 4h; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

hydrogenchloride (7647-01-0) + isoprene epoxide (1838-94-4) → 2-methylbut-2-enal (497-03-0)

isoprene epoxide (1838-94-4) + diluted aqueous sulfuric acid → 2-methylbut-2-enal (497-03-0)

ethylacrolein (922-63-4) + CaCl2 → 2-methylbut-2-enal (497-03-0)

Conditions	Yield
und Destillation;

selenium(IV) oxide (7446-08-4) + 2-methyl-but-2-ene (513-35-9) + benzene (71-43-2) → 2-methylbut-2-enal (497-03-0) + 2-methyl-2-buten-1-ol (497-02-9, 19319-26-7, 4675-87-0) + isoprene (78-79-5) + bis-<2-methyl-buten-(2)-yl-(1)>-selenide

hydrogenchloride (7647-01-0) + methanol (67-56-1) + (E)-1,4-diacetoxy-2-methyl-2-butene (59054-99-8) → 2-methylbut-2-enal (497-03-0)

3-hydroxy-2-methylbutanal (99506-67-9) + sulfuric acid (7664-93-9) → 2-methylbut-2-enal (497-03-0)

Conditions	Yield
Wasserdampfdestillation;

3-hydroxy-2-methylbutanal (99506-67-9) + water (7732-18-5) → 2-methylbut-2-enal (497-03-0)

2-methyl-2-buten-1-ol (497-02-9, 19319-26-7, 4675-87-0) + bromine (7726-95-6) → 2-methylbut-2-enal (497-03-0)

Conditions	Yield
und nachfolgendem Kochen mit Wasser;

diethyl ether (60-29-7) + 3-hydroxy-2-methylbutanal (99506-67-9) + KOH-solution → 2-methylbut-2-enal (497-03-0)

Conditions	Yield
at 30℃;

carbon monoxide (201230-82-2) + 2-diphenylphosphanyl-benzoic acid 1-methyl-allyl ester → 2-methylbut-2-enal (497-03-0) + 2-diphenylphosphanyl-benzoic acid 1,2-dimethyl-3-oxo-propyl ester + 2-diphenylphosphanyl-benzoic acid 1-methyl-4-oxo-butyl ester

Conditions	Yield
With triphenyl phosphite; hydrogen; acetylacetonatodicarbonylrhodium(l) In toluene at 30℃; under 30002.4 Torr; for 46h; Title compound not separated from byproducts;

(E)-2-bromobut-2-ene (3017-71-8) + carbon monoxide (201230-82-2) → 2-methylbut-2-enal (497-03-0)

Conditions	Yield
With N,N,N,N,-tetramethylethylenediamine; hydrogen; catacxium A; palladium diacetate In toluene at 100℃; under 5625.56 Torr; for 16h;	98 % Chromat.

(Z)-2-Bromo-2-butene (3017-68-3) + carbon monoxide (201230-82-2) → 2-methylbut-2-enal (497-03-0)

Conditions	Yield
With N,N,N,N,-tetramethylethylenediamine; hydrogen; catacxium A; palladium diacetate In toluene at 100℃; under 5625.56 Torr; for 16h;	76 % Chromat.

1,1,3-triethoxy-2-methyl-butane (36551-27-6) → 2-methylbut-2-enal (497-03-0)

Conditions	Yield
Multi-step reaction with 2 steps 1: aqueous phosphoric acid; hydroquinone 2: toluene-4-sulfonic acid / 180 °C View Scheme

1-acetoxyl-2-methyl-1,3-butadiene (86400-08-0) → diacetoxy-2-methyl-1,3-butadiene + 2-methylbut-2-enal (497-03-0)

4-penten-3-one (1629-58-9) + acrolein (107-02-8) → 2-methylbut-2-enal (497-03-0)

Ethyl tiglate (5837-78-5) → 2-methylbut-2-enal (497-03-0)

Conditions	Yield
Multi-step reaction with 2 steps 1: lithium aluminium tetrahydride / diethyl ether / 20 °C / Inert atmosphere; Reflux 2: dipyridinium dichromate / dichloromethane / Inert atmosphere; Molecular sieve View Scheme
With lithium aluminium tetrahydride Inert atmosphere;

formic acid (64-18-6) + dimethylacetylene (503-17-3) → 2-methylbut-2-enal (497-03-0)

Conditions	Yield
With dicarbonylacetylacetonato rhodium (I); acetic anhydride; 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene In toluene at 100℃; for 12h; Inert atmosphere; Sealed tube; Glovebox; Darkness; regioselective reaction;	61 %Chromat.

2-methylbut-2-enal (497-03-0) + trimethyl phosphonoacetate (5927-18-4) → methyl (2E,4E)-4-methyl-2,4-hexadienoate (57258-50-1)

Conditions	Yield
Stage #1: trimethyl phosphonoacetate With sodium hydride In benzene at 20℃; for 1.33333h; Stage #2: 2-methylbut-2-enal In benzene for 0.5h; Heating;	100%
With sodium hydride 1.) THF, 2.) RT, 9 h; Multistep reaction;
With sodium hydride In benzene at 65℃; for 4h;	37.82 g

2-methylbut-2-enal (497-03-0) + Chlorodifluoromethyl n-hexyl ketone (86340-68-3) → (E)-5,5-difluoro-4-hydroxy-3-methyl-2-dodecen-6-one (115818-45-6)

Conditions	Yield
With copper(l) chloride; zinc In tetrahydrofuran Heating;	100%
With molecular sieve; copper(l) chloride; zinc In diethyl ether for 3h; Heating;	100%

2-methylbut-2-enal (497-03-0) + (4S,5S)-2,2-dimethyl-4-phenyl-1,3-dioxan-5-amine (35019-66-0) → C17H23NO2

Conditions	Yield
With trifluoroacetic anhydride In benzene for 5h; Inert atmosphere; Dean-Stark; Reflux;	100%

ethyl 3-pyrrolidinobut-2-enoate (2723-42-4, 54716-02-8, 70526-06-6) + 2-methylbut-2-enal (497-03-0) → 5-Methyl-3-((1E,3E)-3-methyl-penta-1,3-dienyl)-isoxazole-4-carboxylic acid ethyl ester

Conditions	Yield
With n-butyllithium; diisopropylamine In tetrahydrofuran; hexane 1.) 0 deg C, 20 min, 2.) -78 deg C, 2 h, 3.) warm to room temperature, 10 h;	99%

2-methylbut-2-enal (497-03-0) + trimethylsilyl cyanide (7677-24-9) → (E)-3-methyl-2-(trimethylsilyloxy)pent-3-enenitrile (74149-67-0)

Conditions	Yield
With potassium carbonate at 20℃; for 6h; Inert atmosphere; Neat (no solvent);	99%
With tetra-(n-butyl)ammonium iodide	92%
With zinc(II) iodide
With zinc(II) iodide
With potassium cyanide; 18-crown-6 ether In dichloromethane

2-methylbut-2-enal (497-03-0) + cyclopenta-1,3-diene (542-92-7) → (1S,2R,3S,4S)-2,3-dimethylbicyclo[2.2.1]hept-5-ene-2-carboxaldehyde

Conditions	Yield
With (R)-3,3'-bis(2-hydroxyphenyl)-2,2'-dihydroxy-1,1'-binaphthyl-boric acid In tetrahydrofuran; dichloromethane at -78℃; for 4h;	99%

2-methylbut-2-enal (497-03-0) + cyclopenta-1,3-diene (542-92-7) → (1S,2R,3S,4R)-2,3-Dimethyl-bicyclo[2.2.1]hept-5-ene-2-carbaldehyde

Conditions	Yield
With (R)-3,3'-di(2-hydroxyphenyl)-2,2'-dihydroxy-1,1'-binaphthyl*B(OMe)3 In tetrahydrofuran; dichloromethane at -78℃; for 4h;	99%
With (R)-3-(2-hydroxy-3-phenylphenyl)-2,2'-dihydroxy-1,1'-binaphthyl*3,5-bis(trifluoromethyl)benzeneboronic acid at -78℃; for 50h;	90%

2-methylbut-2-enal (497-03-0) + benzenesulfonyl cyanide (24224-99-5) → 5-methyl-2-benzenesulfonyl-pyridine

Conditions	Yield
With boric acid In toluene; butan-1-ol	99%

2-methylbut-2-enal (497-03-0) + boric acid tributyl ester (688-74-4) + benzenesulfonyl cyanide (24224-99-5) → 5-methyl-2-benzenesulfonyl-pyridine

Conditions	Yield
In toluene; butan-1-ol	99%
In toluene; butan-1-ol	99%

2-methylbut-2-enal (497-03-0) + N-methylaniline hydrochloride (2739-12-0) → (E)-N-methyl-N-(2-methylbut-2-enyl)benzenamine

Conditions	Yield
Stage #1: 2-methylbut-2-enal; N-methylaniline hydrochloride In methanol at 20℃; for 1h; Stage #2: With triethylsilane; indium(III) chloride In methanol at 20℃; for 24h;	99%

2-methylbut-2-enal (497-03-0) + Camphor (76-22-2) → (1S,4S)-3-((E)-1-Hydroxy-2-methyl-but-2-enyl)-1,7,7-trimethyl-bicyclo[2.2.1]heptan-2-one

Conditions	Yield
	98%

2-methylbut-2-enal (497-03-0) + 1-(N-triisopropylsilyl-1H-indol-3-yl)-N,N-dimethylmethanamine (146886-51-3) → (E)-3-dimethylaminomethyl-4-(1-hydroxy-2-methyl-2-butenyl)-1-triisopropylsilyl-1H-indole (468077-81-8)

Conditions	Yield
Stage #1: 1-(N-triisopropylsilyl-1H-indol-3-yl)-N,N-dimethylmethanamine With tert.-butyl lithium In diethyl ether at -78 - 0℃; Stage #2: 2-methylbut-2-enal In diethyl ether at -78 - 20℃;	98%

2-methylbut-2-enal (497-03-0) + ethyl (triphenylphosphoranylidene)acetate (1099-45-2) → ethyl (2E,4E)-4-methylhexa-2,4-dienoate (149400-42-0, 90107-62-3)

Conditions	Yield
In dichloromethane at 20℃; for 312h; Wittig Olefination;	98%
In dichloromethane at 20℃;	67%

2-methylbut-2-enal (497-03-0) + trimethylsilyl trifluoromethanesulfonate (27607-77-8) → (E)-trimethyl(2-methylbuta-1,3-dienyloxy)silane (54623-57-3)

Conditions	Yield
With triethylamine In dichloromethane at 0 - 20℃; for 5h;	98%

diethoxyphosphoryl-acetic acid ethyl ester (867-13-0) + 2-methylbut-2-enal (497-03-0) → ethyl (2E,4E)-4-methylhexa-2,4-dienoate (149400-42-0, 90107-62-3)

Conditions	Yield
Stage #1: diethoxyphosphoryl-acetic acid ethyl ester With sodium hydride In tetrahydrofuran at 0℃; for 0.5h; Inert atmosphere; Stage #2: 2-methylbut-2-enal In tetrahydrofuran at 0 - 20℃; Inert atmosphere;	97%
With potassium tert-butylate In tetrahydrofuran at 20℃;	90%
With sodium ethanolate In tetrahydrofuran at -20℃; for 0.5h;	90.8%

2-methylbut-2-enal (497-03-0) + 2-Iodomethyl-oxazole-4-carboxylic acid ethyl ester → 2-((1E,3E)-3-Methyl-penta-1,3-dienyl)-oxazole-4-carboxylic acid ethyl ester

Conditions	Yield
With lithium diisopropyl amide; triethylphosphine In N,N-dimethyl-formamide Product distribution; trans/cis selectivity; var. phosphines;	97%
With lithium diisopropyl amide; triethylphosphine 1.) DMF; 2.) DMF; Yield given. Multistep reaction;

2-methylbut-2-enal (497-03-0) + phenyllithium (591-51-5) → α-(1-methyl-1-propenyl)benzenemethanol (80317-46-0)

Conditions	Yield
In tetrahydrofuran at 0℃; for 4h;	96%

2-methylbut-2-enal (497-03-0) + N-isopropyl oxazolidinone (77877-19-1) → (4S,2'S,3'S,4'E)-3-(2',4'-dimethyl-3'-hydroxy-1'-oxo-4'-hexenyl)-4-isopropyl-2-oxazolidinone (694440-08-9)

Conditions	Yield
Stage #1: N-isopropyl oxazolidinone With di-n-butylboryl trifluoromethanesulfonate; triethylamine In dichloromethane at -3℃; for 1h; Stage #2: 2-methylbut-2-enal In dichloromethane at -78 - 0℃; for 2h; Stage #3: With dihydrogen peroxide In methanol; phosphate buffer; dichloromethane at 0℃; for 1h; pH=7; Further stages.;	96%
Stage #1: N-isopropyl oxazolidinone With di-n-butylboryl trifluoromethanesulfonate; N-ethyl-N,N-diisopropylamine In dichloromethane at 0℃; for 0.5h; Stage #2: 2-methylbut-2-enal In dichloromethane at -78 - 20℃; for 2h; Stage #3: With dihydrogen peroxide In methanol; phosphate buffer; dichloromethane at 0℃; for 1h; pH=7;	94%
Stage #1: N-isopropyl oxazolidinone With di-n-butylboryl trifluoromethanesulfonate; N-ethyl-N,N-diisopropylamine In diethyl ether; dichloromethane at 0℃; for 0.5h; Inert atmosphere; Stage #2: 2-methylbut-2-enal In diethyl ether; dichloromethane at -78 - 20℃; for 2h;

N-methylmaleimide (930-88-1) + 2-methylbut-2-enal (497-03-0) + phenylacetyl chloride (103-80-0) → 2,3,3a,4,7,7a-hexahydro-2,6-dimethyl-1,3-dioxo-1H-isoindol-7-yl 2-phenylacetate

Conditions	Yield
Stage #1: 2-methylbut-2-enal; phenylacetyl chloride With potassium n-butoxide In tetrahydrofuran at -78℃; for 0.5h; Stage #2: N-methylmaleimide In tetrahydrofuran at 60℃; for 16h;	96%

Benzyl N-hydroxycarbamate (3426-71-9) + 2-methylbut-2-enal (497-03-0) → benzyl 5-hydroxy-3,4-dimethylisoxazolidin-2-carboxylate

Conditions	Yield
With pyrrolidine In chloroform at 20℃; for 144h;	96%

1-ethenylcyclohexene (931-49-7) + 2-methylbut-2-enal (497-03-0) → (4E)-1-cyclohexenyl-4-methylhex-4-en-1-yn-3-ol (1237836-86-0)

Conditions	Yield
Stage #1: 1-ethenylcyclohexene With n-butyllithium In diethyl ether; hexane at -78℃; Inert atmosphere; Stage #2: 2-methylbut-2-enal In diethyl ether; hexane at -78 - 20℃; Inert atmosphere;	95%

2-methylbut-2-enal (497-03-0) + benzylamine (100-46-9) → Benzyl-((E)-2-methyl-but-2-enyl)-amine (107175-79-1)

Conditions	Yield
Stage #1: 2-methylbut-2-enal; benzylamine With magnesium sulfate In dichloromethane at 20℃; for 1h; Inert atmosphere; Stage #2: With sodium tetrahydroborate In methanol at 0 - 20℃; for 16h; Inert atmosphere;	95%

2-methylbut-2-enal (497-03-0) + allyl bromide (106-95-6) → (E)-5-methyl-1,5-heptadien-4-ol (62036-50-4)

Conditions	Yield
With zinc In diethyl ether at 0℃; for 6h;	94%
With diethyl ether; zinc
Stage #1: allyl bromide With indium(III) chloride; 4,4'-di-tert-butylbiphenyl In tetrahydrofuran for 0.5h; Stage #2: 2-methylbut-2-enal In tetrahydrofuran at 25℃; for 0.5h;	91 %Chromat.

2-methylbut-2-enal (497-03-0) + (4R,5S)-4-methyl-5-phenyl-3-propionyloxazolidin-2-one (77877-20-4) → (4R,5S,2'R,3'R,4'E)-3-(2',4'-dimethyl-3'-hydroxy-1'-oxo-4'-hexenyl)-4-methyl-5-phenyl-2-oxazolidinone (694440-05-6)

Conditions	Yield
Stage #1: (4R,5S)-4-methyl-5-phenyl-3-propionyloxazolidin-2-one With di-n-butylboryl trifluoromethanesulfonate; N-ethyl-N,N-diisopropylamine In dichloromethane at 0℃; for 0.5h; Stage #2: 2-methylbut-2-enal In dichloromethane at -78 - 20℃; for 2h; pH=7; Stage #3: With dihydrogen peroxide In phosphate buffer; dichloromethane at 0℃; for 1h;	94%
Stage #1: (4R,5S)-4-methyl-5-phenyl-3-propionyloxazolidin-2-one With di-n-butylboryl trifluoromethanesulfonate; triethylamine In dichloromethane at -10 - 0℃; for 2.08333h; Stage #2: 2-methylbut-2-enal In dichloromethane at -78 - 20℃;	89%
Stage #1: (4R,5S)-4-methyl-5-phenyl-3-propionyloxazolidin-2-one With di-n-butylboryl trifluoromethanesulfonate; triethylamine In dichloromethane at 0℃; for 1h; Stage #2: 2-methylbut-2-enal In dichloromethane at -78 - 0℃; for 2h; Stage #3: With dihydrogen peroxide In methanol; phosphate buffer; dichloromethane at 0℃; for 1h; pH=7; Further stages.;	88%

2-methylbut-2-enal (497-03-0) + mesityllithium (5806-59-7) → E-1-mesityl-2-methyl-2-buten-1-ol (84061-27-8)

Conditions	Yield
	94%

2-methylbut-2-enal (497-03-0) + methyl 2-(triphenylphosphoranylidene)propionate (2605-68-7) → (E,E)-methyl 2,4-dimethylhexa-2,4-dienoate (102103-76-4)

Conditions	Yield
In dichloromethane for 48h; Heating;	94%
In dichloromethane for 48h; Heating;	73%
In dichloromethane at 40℃; for 18h;	70%

2-methylbut-2-enal (497-03-0) + phenethylmagnesium chloride (90878-19-6) → (+/-)-(E)-4-methyl-1-phenylhex-4-en-3-ol (181573-12-6)

Conditions	Yield
Stage #1: 2-methylbut-2-enal; phenethylmagnesium chloride In tetrahydrofuran at 0 - 20℃; for 2h; Inert atmosphere; Stage #2: With ammonium chloride In tetrahydrofuran; water at 0℃;	94%
In tetrahydrofuran at 0 - 20℃;	82%

2-methylbut-2-enal (497-03-0) + n-octyne (629-05-0) → (E)-3-methyldodec-2-en-5-yn-4-ol (1237836-84-8)

Conditions	Yield
Stage #1: n-octyne With n-butyllithium In diethyl ether; hexane at -78℃; Inert atmosphere; Stage #2: 2-methylbut-2-enal In diethyl ether; hexane at -78 - 20℃; Inert atmosphere;	94%

1,3 dithiane (505-23-7) + 2-methylbut-2-enal (497-03-0) → (E)-1-(1,3-dithian-2-yl)-2-methylbut-2-en-1-ol (1351557-44-2)

Conditions	Yield
Stage #1: 1,3 dithiane With n-butyllithium In tetrahydrofuran; hexane at -20℃; for 1h; Inert atmosphere; Stage #2: 2-methylbut-2-enal In tetrahydrofuran; hexane at -78℃; for 0.5h; Inert atmosphere;	94%

Upstream product

• 7647-01-0 hydrogenchloride 
• 67-56-1 methanol 
• 59054-99-8 (E)-1,4-diacetoxy-2-methyl-2-butene 
• 99506-67-9 3-hydroxy-2-methylbutanal 
• 7664-93-9 sulfuric acid 
• 7732-18-5 water 
• 497-02-9 2-methyl-2-buten-1-ol 
• 7726-95-6 bromine 
• 60-29-7 diethyl ether 
• 1629-58-9 4-penten-3-one 
• 107-02-8 acrolein 
• 7632-16-8 (2S,4S)-carveol 
• 2102-58-1 (+)-trans-carveol 
• 64197-53-1 3-ethoxy-2-methylbutanal 

Downstream Products

• 136175-35-4 (E)-3,3,5-Trimethyl-hept-5-ene-1,4-diol 
• 56058-69-6 (+/-)-Ocimenoyl oxide 
• 145652-82-0 (E)-1-diphenylphosphinoyl-3-methylpent-3-en-2-ol 
• 149400-42-0 ethyl (2E,4E)-4-methylhexa-2,4-dienoate 
• 760984-68-7 (4R,5S,2'S,3'R,4'E)-3-(2',4'-dimethyl-3'-hydroxy-1'-oxo-4'-hexenyl)-4-methyl-5-phenyl-2-oxazolidinone 
• 911422-79-2 1-(dimethyl-phenyl-silanyl)-3-methyl-pent-3-en-2-one 
• 911422-68-9 (S)-1-(dimethyl-phenyl-silanyl)-3-methyl-pent-3-en-2-ol 
• 911422-69-0 (R)-6-(dimethyl-phenyl-silanyl)-3,4-dimethyl-hex-4-enal 
• 911422-70-3 (S,R)-2-[6-(dimethyl-phenyl-silanyl)-1-hydroxy-3,4-dimethyl-hex-4-enyl]-cyclohex-2-enone 
• 106477-57-0 4-((Ξ)-2-methyl-but-2t-enylidene)-2-phenyl-4H-oxazol-5-one 

Relevant articles and documents

(±)-Camphor sulfonic acid assisted IBX based oxidation of 1° and 2° alcohols

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Rhodium-catalyzed hydroformylation of alkynes employing a self-assembling ligand system

Hydroformylation of alkynes is an underdeveloped atom-economic and redox-neutral method to prepare enals. Applying a new electron poor self-assembling ligand system provides the first general rhodium-catalyst for the chemo- and stereoselective hydroformylation of dialkyl- as well as diaryl-substituted alkynes to furnish enals in excellent chemo- and stereoselectivity.