6728-31-0

Basic information

• Product Name: CIS-4-HEPTENAL
• Synonyms: FEMA 3289;CIS-4-HEPTEN-1-AL;CIS-4-HEPTENAL;C4 HEPTENAL;TIMTEC-BB SBB006608;(4Z)-4-Heptenal;(Z)-4-Hepten-1-al;(z)-4-heptena
• CAS NO: 6728-31-0
• Molecular Formula: C₇H₁₂O
• Molecular Weight: 112.17
• EINECS: 229-779-7
• Product Categories: Alphabetical Listings;Flavors and Fragrances;G-H;Alpha Sort;E-L;Volatiles/ Semivolatiles
• Mol File: 6728-31-0.mol
• Article Data: 8

Chemical Properties

• Melting Point: -53.35°C (estimate)
• Boiling Point: 60 °C25 mm Hg(lit.)
• Flash Point: 105 °F
• Appearance: Clear colorless to light yellow/Liquid
• Density: 0.850 g/mL at 20 °C(lit.)
• Vapor Pressure: 3.64mmHg at 25°C
• Refractive Index: n20/D 1.434
• Storage Temp.: 0-6°C
• BRN: 1902614
• CAS DataBase Reference: CIS-4-HEPTENAL(CAS DataBase Reference)
• NIST Chemistry Reference: CIS-4-HEPTENAL(6728-31-0)
• EPA Substance Registry System: CIS-4-HEPTENAL(6728-31-0)

Safety Data

• Statements: 10
• Safety Statements: 16-24/25
• RIDADR: UN 1989 3/PG 3
• WGK Germany: 3
• F: 10-23
• HazardClass: 3
• PackingGroup: III
• Hazardous Substances Data: 6728-31-0(Hazardous Substances Data)

Usage

Description

CIS-4-HEPTENAL is a chemical compound with a distinctive fried, buttery flavor and an odor reminiscent of heptaldehyde. It is prepared from Hemiptera insects (trans-form) and through a series of chemical reactions involving pen-ten-l-en-3-ol and a Claisen rearrangement to 4-heptenal (transform). CIS-4-HEPTENAL is commonly used to impart a fried, buttery flavor to various food products.

Uses

Used in Food Industry:
CIS-4-HEPTENAL is used as a flavoring agent for imparting a fried, buttery taste to food products. Its unique aroma and flavor profile make it a popular choice for enhancing the taste of various dishes and ingredients.
Used in Aromatherapy:
CIS-4-HEPTENAL is also used in aromatherapy for its pleasant and soothing scent. It can be incorporated into essential oil blends or used in diffusers to create a calming and relaxing atmosphere.
Used in Perfumery:
In the perfumery industry, CIS-4-HEPTENAL is used as a fragrance ingredient to add depth and complexity to perfumes and colognes. Its unique aroma can contribute to the creation of long-lasting and memorable scents.
Used in Cosmetics:
CIS-4-HEPTENAL can be used in cosmetics as a scent component to add a pleasant aroma to products such as lotions, creams, and body washes. Its buttery scent can provide a luxurious and indulgent experience for users.
Used in Flavor and Fragrance Development:
In the research and development of new flavors and fragrances, CIS-4-HEPTENAL can be used as a key component to create innovative and unique scents and tastes. Its versatility allows it to be combined with other compounds to develop new products for various industries.

Preparation

From Hemiptera bugs (trans-form); from penten-1-en-3-ol converted to the corresponding vinyl ether, which undergoes a Claisen rearrangement to 4-heptenal (trans-form).

InChI:InChI=1/C7H12O/c1-2-3-4-5-6-7-8/h3-4,7H,2,5-6H2,1H3/b4-3-

Synthetic route

(Z)-4-hepten-1-ol (6191-71-5) → (Z)-4-heptenal (6728-31-0)

7,7-diethoxy-hept-3c-ene (18492-65-4) → (Z)-4-heptenal (6728-31-0)

Conditions	Yield
With formic acid

2-hex-3-enyl-4,4,6-trimethyl-[1,3]oxazinane (36872-14-7) → (Z)-4-heptenal (6728-31-0)

Conditions	Yield
With oxalic acid

(Z)-3-Hexen-1-ol (928-96-1) → (Z)-4-heptenal (6728-31-0)

Conditions	Yield
Multistep reaction;
Multi-step reaction with 3 steps 1: PBr3, Py 2: (i) Mg, (ii) /BRN= 1719716/ 3: HCO2H View Scheme

(Z)-1-Bromo-3-hexene (5009-31-4) + carbon monoxide (201230-82-2) → (Z)-4-heptenal (6728-31-0)

Conditions	Yield
With 2,2'-azobis(isobutyronitrile); tri-n-butyl-tin hydride In benzene at 80℃; under 49400 Torr; for 3h;	80 % Chromat.

(Z)-2-(hept-4-en-1-yloxy)tetrahydro-2H-pyran (530086-82-9) → (Z)-4-heptenal (6728-31-0)

Conditions	Yield
Multi-step reaction with 2 steps 1: 74 percent / conc. H2SO4 / acetone; H2O / 20 °C 2: 65 percent / NACAA / CH2Cl2; pyridine / 0.33 h / 20 °C View Scheme
Multi-step reaction with 2 steps 1: toluene-4-sulfonic acid / methanol / 15 h / 20 °C 2: 2,2,6,6-Tetramethyl-1-piperidinyloxy free radical; [bis(acetoxy)iodo]benzene / dichloromethane / 1 h / 20 °C View Scheme

1-bromo-pent-2-yne (16400-32-1) → (Z)-4-heptenal (6728-31-0)

Conditions	Yield
Multi-step reaction with 5 steps 1: 60 percent / benzene / 12 h / Heating 2: 65 percent / NaCl, H2O / dimethylsulfoxide / 8 h / 160 °C 3: 76 percent / LAH, EtOH / diethyl ether 4: 80 percent / H2, quinoline / Lindlar's catalyst / hexane 5: 58 percent / pyridinium chlorochromate, NaOAc / CH2Cl2 / 4 h View Scheme

hept-4-yn-1-ol (42397-24-0) → (Z)-4-heptenal (6728-31-0)

Conditions	Yield
Multi-step reaction with 2 steps 1: 80 percent / H2, quinoline / Lindlar's catalyst / hexane 2: 58 percent / pyridinium chlorochromate, NaOAc / CH2Cl2 / 4 h View Scheme

pent-2-yn-1-ol (6261-22-9) → (Z)-4-heptenal (6728-31-0)

Conditions	Yield
Multi-step reaction with 6 steps 1: 77 percent / PBr3, pyridine / diethyl ether / Ambient temperature 2: 60 percent / benzene / 12 h / Heating 3: 65 percent / NaCl, H2O / dimethylsulfoxide / 8 h / 160 °C 4: 76 percent / LAH, EtOH / diethyl ether 5: 80 percent / H2, quinoline / Lindlar's catalyst / hexane 6: 58 percent / pyridinium chlorochromate, NaOAc / CH2Cl2 / 4 h View Scheme

ethyl 2-carbethoxy-hept-4-yn-1-oate (98442-18-3) → (Z)-4-heptenal (6728-31-0)

Conditions	Yield
Multi-step reaction with 4 steps 1: 65 percent / NaCl, H2O / dimethylsulfoxide / 8 h / 160 °C 2: 76 percent / LAH, EtOH / diethyl ether 3: 80 percent / H2, quinoline / Lindlar's catalyst / hexane 4: 58 percent / pyridinium chlorochromate, NaOAc / CH2Cl2 / 4 h View Scheme

ethyl hept-4-yn-1-oate (98442-19-4) → (Z)-4-heptenal (6728-31-0)

Conditions	Yield
Multi-step reaction with 3 steps 1: 76 percent / LAH, EtOH / diethyl ether 2: 80 percent / H2, quinoline / Lindlar's catalyst / hexane 3: 58 percent / pyridinium chlorochromate, NaOAc / CH2Cl2 / 4 h View Scheme

(Z)-4-Heptensaeure-ethylester (39924-27-1) → (Z)-4-heptenal (6728-31-0)

Conditions	Yield
Multi-step reaction with 2 steps 1: 82 percent / LiAlH4 / diethyl ether 2: 76 percent / pyridinium chlorochromate / CH2Cl2 / 2 h View Scheme

(Z)-1-Bromo-3-hexene (5009-31-4) → (Z)-4-heptenal (6728-31-0)

Conditions	Yield
Multi-step reaction with 2 steps 1: (i) Mg, (ii) /BRN= 1719716/ 2: HCO2H View Scheme

hept-4-ynal → (Z)-4-heptenal (6728-31-0)

Conditions	Yield
With hydrogen In ethanol	10.5 g (94%)

(Z)-4-heptenal (6728-31-0) + ethyl acetate (141-78-6) → ethyl (+/-)-(Z)-3-hydroxy-non-6-enoate (1202014-45-6)

Conditions	Yield
Stage #1: ethyl acetate With lithium diisopropyl amide In tetrahydrofuran; hexane at -78℃; for 0.333333h; Stage #2: (Z)-4-heptenal In tetrahydrofuran; hexane at -78℃; for 2h;	100%

(Z)-4-heptenal (6728-31-0) + benzoic acid (65-85-0) + Tert-butyl isocyanate (1609-86-5) → (Z)-1-(tert-butylcarbamoyl)hept-4-enyl benzoate

Conditions	Yield
In tetrahydrofuran at 20℃;	99%

p-toluene sulfinic acid (536-57-2) + (Z)-4-heptenal (6728-31-0) + benzamide (55-21-0) → (Z)-N-(1-tosylhept-4-enyl)benzamide (1000681-66-2)

Conditions	Yield
With magnesium sulfate In dichloromethane at 20℃;	99%

methanol (67-56-1) + (Z)-4-heptenal (6728-31-0) + dibenzyl azodicarboxylate (2449-05-0) → benzyl (S,Z)-(2-oxo-4-(pent-2-en-1-yl)oxazolidin-3-yl)carbamate + benzyl (R,Z)-(2-oxo-4-(pent-2-en-1-yl)oxazolidin-3-yl)carbamate

Conditions	Yield
Stage #1: (Z)-4-heptenal; dibenzyl azodicarboxylate With D-Prolin In acetonitrile at 0℃; for 0.5h; Stage #2: methanol With sodium tetrahydroborate In acetonitrile at 0℃; for 2.63333h; Stage #3: With sodium hydroxide In acetonitrile at 20℃; for 3h; enantioselective reaction;	A 99% B n/a

nitromethane (75-52-5) + (Z)-4-heptenal (6728-31-0) → (+/-)-(Z)-1-nitrooct-5-en-2-ol (925210-18-0)

Conditions	Yield
With potassium tert-butylate In tetrahydrofuran; nitromethane; tert-butyl alcohol at 20℃; for 1h; Henry reaction;	98%
With potassium tert-butylate In tetrahydrofuran; tert-butyl alcohol Henry reaction;

(Z)-4-heptenal (6728-31-0) + bis-(2,2,2-trifluoroethyl)(methoxycarbonylmethyl)phosphonate (88738-78-7) → C10H16O2 (1170320-52-1)

Conditions	Yield
With 18-crown-6 ether; potassium hexamethylsilazane In tetrahydrofuran at -78℃; Still-Gennari reaction;	98%

(Z)-4-heptenal (6728-31-0) + phenylmagnesium bromide → (Z)-1-phenylhept-4-en-1-ol (151322-33-7)

Conditions	Yield
In diethyl ether for 0.333333h; Heating;	97%

(Z)-4-heptenal (6728-31-0) + (R)-2-methylpropane-2-sulfinamide (196929-78-9) → (R)-N-[(Z)-hept-4-en-(E)-ylidene]-(2-tert-butane)sulfinamide (949886-14-0)

Conditions	Yield
With copper(II) sulfate In dichloromethane at 20℃;	97%

(Z)-4-heptenal (6728-31-0) + benzylmagnesium chloride (6921-34-2) → (Z)-1-phenyl-5-octen-2-ol (151322-34-8)

Conditions	Yield
In diethyl ether for 0.333333h; Heating;	96%
In tetrahydrofuran Heating;

1-nitrohexane (646-14-0) + (Z)-4-heptenal (6728-31-0) → (Z)-8-nitrotridec-3-en-7-ol

Conditions	Yield
With sodium hydroxide; cetyltrimethylammonium chloride for 3h; Ambient temperature;	95%

(Z)-4-heptenal (6728-31-0) + allylmagnesium bromide (1730-25-2) → (7Z)-1,7-decadien-4-ol (670227-73-3)

Conditions	Yield
In diethyl ether at 0 - 20℃; for 0.583333h;	95%

(Z)-4-heptenal (6728-31-0) + allyltributylstanane (24850-33-7) → (7Z)-1,7-decadien-4-ol (670227-73-3)

Conditions	Yield
With cerium(III) chloride; sodium iodide In acetonitrile at 20℃; for 25.5h;	93%

(Z)-4-heptenal (6728-31-0) + methyl (triphenylphosphoranylidene)acetate (21204-67-1) → Methyl-6Z,2E-nonadienoat (41654-18-6)

Conditions	Yield
In dichloromethane at 40℃;	93%

(Z)-4-heptenal (6728-31-0) + vinyl magnesium bromide (1826-67-1) + methyl chloroformate (79-22-1) → (Z)-methyl nona-1,6-dien-3-yl carbonate

Conditions	Yield
Stage #1: (Z)-4-heptenal; vinyl magnesium bromide In tetrahydrofuran; diethyl ether at 0℃; for 0.5h; Inert atmosphere; Stage #2: methyl chloroformate In tetrahydrofuran; diethyl ether at 20℃; for 2h; Inert atmosphere;	92%

(Z)-4-heptenal (6728-31-0) + allyldimethylphenylsilane (18001-18-8) → 3-dimethylphenylsilyl-deca-1,7-dien-4-ol

Conditions	Yield
Stage #1: allyldimethylphenylsilane With n-butyllithium In tetrahydrofuran; hexane at 20℃; for 0.25h; Stage #2: With triisopropoxytitanium(IV) chloride In tetrahydrofuran; hexane at -78℃; for 0.333333h; Stage #3: (Z)-4-heptenal In tetrahydrofuran; hexane at -78℃; for 1.5h; Further stages.;	88%

Nitroethane (79-24-3) + (Z)-4-heptenal (6728-31-0) → (Z)-2-Nitro-non-6-en-3-ol (138668-11-8, 138668-22-1)

Conditions	Yield
With Amberlyst A-21 for 6h;	87%

trimethylsilyl cyanide (7677-24-9) + (Z)-4-heptenal (6728-31-0) → (Z)-1-aminooct-5-en-2-ol

Conditions	Yield
Stage #1: trimethylsilyl cyanide; (Z)-4-heptenal With potassium cyanide; 18-crown-6 ether In dichloromethane at 25℃; for 3h; Stage #2: With lithium aluminium tetrahydride In diethyl ether at 25℃; for 7h;	86%

(Z)-4-heptenal (6728-31-0) + (2R,3R)-3-Hydroxy-4-(4-methoxy-phenoxy)-2-methyl-butyric acid (779356-69-3) → (5R,6R)-2-((Z)-Hex-3-enyl)-6-(4-methoxy-phenoxymethyl)-5-methyl-[1,3]dioxan-4-one

Conditions	Yield
Stage #1: (2R,3R)-3-Hydroxy-4-(4-methoxy-phenoxy)-2-methyl-butyric acid With 1,1,1,3,3,3-hexamethyl-disilazane In dichloromethane at 35℃; for 18h; Stage #2: (Z)-4-heptenal With 2,6-di-tert-butyl-4-methylpyridine; trimethylsilyl trifluoromethanesulfonate In dichloromethane at -78℃; for 0.5h; Stage #3: With trifluorormethanesulfonic acid In dichloromethane	86%

(Z)-4-heptenal (6728-31-0) + (2R,3R)-3-Hydroxy-4-(4-methoxy-phenoxy)-2-methyl-butyric acid (779356-69-3) → C19H26O5 (779356-70-6) + C19H26O5

Conditions	Yield
Stage #1: (2R,3R)-3-Hydroxy-4-(4-methoxy-phenoxy)-2-methyl-butyric acid With 1,1,1,3,3,3-hexamethyl-disilazane In dichloromethane at 20 - 35℃; for 18h; Inert atmosphere; Stage #2: (Z)-4-heptenal With 2,6-di-tert-butyl-4-methylpyridine; trimethylsilyl trifluoromethanesulfonate In dichloromethane at -78℃; for 0.5h; Inert atmosphere; optical yield given as %de;	A 86% B n/a

(Z)-4-heptenal (6728-31-0) + methyl 2-cyanoacetate (105-34-0) → methyl (Z)-2-amino-5-(pent-2-en-1-yl)thiophene-3-carboxylate

Conditions	Yield
With sulfur; triethylamine for 12h; Gewald Aminoheterocycles Synthesis; Reflux; Inert atmosphere;	86%

(Z)-4-heptenal (6728-31-0) + acetylenemagnesium bromide (4301-14-8) → (Z)-non-6-en-1-yn-3-ol

Conditions	Yield
In tetrahydrofuran at 0℃; for 5h;	86%

(Z)-4-heptenal (6728-31-0) + 1-phenylsulfonyl-2-propanone (5000-44-2) → (7Z)-4-hydroxy-1-phenylsulfonyl-7-decen-2-one (797752-54-6)

Conditions	Yield
Stage #1: 1-phenylsulfonyl-2-propanone With N,N,N,N,N,N-hexamethylphosphoric triamide; lithium diisopropyl amide In tetrahydrofuran; hexane at 0℃; for 4h; Stage #2: (Z)-4-heptenal In tetrahydrofuran; hexane at 0 - 20℃; Further stages.;	85%

(Z)-4-heptenal (6728-31-0) → (R,Z)-hept-4-ene-1,2-diol (1214888-17-1)

Conditions	Yield
Stage #1: (Z)-4-heptenal With Nitrosobenzene; L-proline In chloroform at 0℃; for 2h; Stage #2: With sodium tetrahydroborate In ethanol; chloroform at 0℃; for 2h; Stage #3: With acetic acid; zinc In ethanol at 20℃; for 16h;	84%

(Z)-4-heptenal (6728-31-0) → (Z)-4-hepten-1-ol (6191-71-5)

Conditions	Yield
With sodium tetrahydroborate In methanol at 0℃; for 0.5h;	84%

1-benzofurane (271-89-6) + (Z)-4-heptenal (6728-31-0) → (Z)-1-(benzofuran-2-yl)hept-4-en-1-ol

Conditions	Yield
Stage #1: 1-benzofurane With n-butyllithium In diethyl ether; hexane at -78 - 20℃; for 3.75h; Inert atmosphere; Stage #2: (Z)-4-heptenal In diethyl ether; hexane at -78℃; for 1.5h; Inert atmosphere;	84%

(Z)-4-heptenal (6728-31-0) + 2-(but-3-en-2-yl)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol → (S,8Z)-undeca-2,8-dien-5-ol

Conditions	Yield
With (R)-10-camphorsulfonic acid In dichloromethane at 25℃; for 96h;	83%

(Z)-4-heptenal (6728-31-0) + methylmagnesium bromide (75-16-1)

Conditions	Yield
Stage #1: (Z)-4-heptenal; methylmagnesium bromide In tetrahydrofuran; toluene at -78 - 20℃; Stage #2: With water; ammonium chloride In tetrahydrofuran; toluene	83%

(Z)-4-heptenal (6728-31-0) + 4-flourophenylmagnesium bromide (352-13-6) → (Z)-1-(4-fluorophenyl)hept-4-en-1-ol

Conditions	Yield
In tetrahydrofuran; diethyl ether at 0 - 20℃; for 1h;	83%

cyclohexenone (930-68-7) + (Z)-4-heptenal (6728-31-0) → 2-((R,Z)-1-hydroxyhept-4-enyl)cyclohex-2-enone

Conditions	Yield
Stage #1: cyclohexenone; (R)-1-(3,5-bis(trifluoromethyl)phenyl)-3-(1-(2-(dimethylamino)naphthalen-1-yl)naphthalen-2-yl)thiourea In acetonitrile at 0℃; for 0.166667h; Baylis-Hillman Reaction; Stage #2: (Z)-4-heptenal In acetonitrile for 72h; Product distribution / selectivity;	82%

(Z)-4-heptenal (6728-31-0) + eschenmoser's salt (33797-51-2) → (Z)-2-methylenehept-4-enal

Conditions	Yield
With triethylamine In dichloromethane at 20℃; for 15h;	80%

Upstream product

• 928-96-1 (Z)-3-Hexen-1-ol 
• 5009-31-4 (Z)-1-Bromohex-3-ene 
• 201230-82-2 carbon monoxide 
• 21891-36-1 hept-4-ynal 
• 39924-27-1 (Z)-4-Heptensaeure-ethylester 
• 98442-19-4 ethyl hept-4-yn-1-oate 
• 98442-18-3 ethyl 2-carbethoxy-hept-4-yn-1-oate 
• 6261-22-9 pent-2-yn-1-ol 
• 42397-24-0 hept-4-yn-1-ol 
• 16400-32-1 1-bromo-pent-2-yne 
• 530086-82-9 (Z)-2-(hept-4-en-1-yloxy)tetrahydro-2H-pyran 
• 6191-71-5 (Z)-4-hepten-1-ol 
• 36872-14-7 2-hex-3-enyl-4,4,6-trimethyl-[1,3]oxazinane 
• 18492-65-4 7,7-diethoxy-hept-3c-ene 

Downstream Products

• 4868-21-7 undec-8c-ene-2,5-dione 
• 138668-11-8 (Z)-2-Nitro-non-6-en-3-ol 
• 586961-62-8 trans-3-ethyl-2-phenylcyclohexanone 
• 586961-60-6 benzyl (Z)-3-hexenyl ketone 
• 34019-86-8 (Z)-6-Nonen-2-one 
• 41031-87-2 (Z)-4-oxodec-7-enal 
• 1208882-46-5 N-((2R,3R)-2-hydroxy-3-((Z)-pent-2-enyl)-2,3-dihydrobenzofuran-5-yl)-4-methylbenzenesulfonamide 
• 6191-71-5 (Z)-4-hepten-1-ol 
• 55968-41-7 cis-5-octen-2-ol 
• 779356-70-6 C₁₉H₂₆O₅ 
• 23605-13-2 (2E,6Z)-2,6-nonadienoic acid 

Relevant articles and documents

Synthesis method of aggregation pheromone (E)-cis-6, 7-epoxy-2-nonenal of Aromia bungii

The invention relates to a synthesis method of aggregation pheromone (E)-cis-6, 7-epoxy-2-nonenal of Aromia bungii, which belongs to the field of pharmaceutical synthesis. The synthesis method comprises the following steps: taking 1, 4-butanediol as a raw material, singly protecting diol with DHP (dihexylphthalate) and then oxidizing TEMPO (tetramethylpiperidine oxide) into 4-((tetrahydro-2H-pyran-2-base) oxy) butyraldehyde; performing a Wittig reaction, so as to obtain (Z)-2-(hepta-4- alkene-1-base-oxy) tetrahydro-2H-pyran; removing the protection of the DHP and oxidizing TEMPO, so as to obtain (Z)-4-heptenal; performing a Wittig reaction, so as to obtain (2E, 6Z)-nona-2, 6-heptadienal; finally, performing epoxidation, so as to obtain the aggregation pheromone (E)-cis-6, 7-epoxy-2-nonenalof the Aromia bungii. The total yield is 6.5%. In the synthesis method, the 1, 4-butanediol with low cost is taken as the starting raw material; the synthesis method has the advantages of being simple in operation and mild in conditions, therefore, the synthesis method is suitable for large-scale preparation.

A study of 1,5-hydrogen shift and cyclization reactions of an alkali isomerized methyl linolenoate

Heating a mixture formed by alkali isomerization of methyl linolenoate (1) produces a complex mixture with the bicyclic hexahydroindenoic esters 4β-(7-methoxycarbonylheptyl)-5α-methyl-2,3,3aα,4,5, 7aαhexahydroindene (CL5) and 4β-ethyl-5α-(6-methoxycarbonylhexyl)-2,3,3aα,4,5, 7aα-hexahydroindene (CL6) as main components. Similar isomerization reactions of three synthetic model compounds, methyl 9Z,13E,15Z-octadecatrienoate (2), 9Z,14E,16E-octadecatrienoate (4) and 9Z,11E,15Z-octadecatrienoate (5) corroborated the results obtained with alkali isomerized methyl linolenoate.

A New Synthesis of Nona-2E,6Z-dienal

Monosodio ethyl malonate on alkylation with 1-bromo-pent-2-yne (III) furnishes the diester (IV) which on decarbethoxylation with NaCl/DMSO, followed by LAH/EtOH reduction of the resultant ester (V), yields the carbinol (VI).Hydrogenation of VI in the presence of Lindlar's catalyst produces hept-4Z-en-1-ol (VII), which on pyridinium chlorochromate oxidation gives the aldehyde (VIII).Wittig-Horner reaction on VIII using ethyl diethylphosphonoacetate produces the dienoate (IX), which on LAH/EtOH reduction followed by oxidation with Corey's reagent, affords the title compound(I).