5307-99-3

Usage

Chemical Properties

clear brown liquid

Synthesis

Under nitrogen protection, to a solution of dichloracetyl chloride (34 g, 0.23 mol) and cyclopentadiene(60 ml, 0.7 mol) in pentane (230 ml), heated to reflux in a three-necked flask with constant pressure funnel and condenser tube, was added dropwise via funnel triethylamine (24 g, 0.24 mol) in pentane (100 ml) with mechanical stirring during 4 hours, and a lot of white triethylamine hydrochloride was produced. After reflux for 2 hours, water (80 ml) was added to dissolve the triethylamine hydrochloride. The reaction mixture was extracted with pentane (2 × 60ml). The combined extracts were filtered and dried over anhydrous Na2SO4, and concentrated in vacuo to give brownish black oil. Fraction of reduced pressure distillation at 83~87 °C/400 Pa was collected to give 7,7-Dichlorobicyclo[3.2.0]hept-2-en-6-one (2, 33.5 g) as a colorless oil.

InChI:InChI=1/C7H6Cl2O/c8-7(9)5-3-1-2-4(5)6(7)10/h1,3-5H,2H2/t4-,5+/m1/s1

Synthetic route

tributyl(trichloroacetoxy)stannane (4342-33-0) + cyclopenta-1,3-diene (542-92-7) → (+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) + tributyltin chloride (1461-22-9) + Triphenylphosphine oxide (791-28-6)

Conditions	Yield
With triphenylphosphine	A 30% B 90% C 92%
With P(C6H5)3	A 30% B 90% C 92%

dichloroacethyl chloride (79-36-7) + cyclopenta-1,3-diene (542-92-7) → (+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3)

Conditions	Yield
With triethylamine In pentane for 4h; Heating;	88%
With triethylamine In hexane; n-heptane at 20℃;	86%
With triethylamine In hexane at 20℃;	85%

β,β-dichloroacryloyl chloride (20618-08-0) + cyclopenta-1,3-diene (542-92-7) → (+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3)

Conditions	Yield
With triethylamine In hexane at 26 - 30℃; for 9h;	85%

dichloroketene (4591-28-0) + cyclopenta-1,3-diene (542-92-7) → (+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3)

Conditions	Yield
With triethylamine In pentane	79%

cyclopenta-1,3-diene (542-92-7) + Trichloroacetyl chloride (76-02-8) → (+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3)

Conditions	Yield
With zinc In diethyl ether at 0℃; for 1h;	61%

7,7-dichloro-2,4-exo-bis(trimethylsilyl)bicyclo<3.2.0>hept-2-en-6-one (78133-61-6) → (+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3)

Conditions	Yield
With sulfuric acid In methanol for 18h; Ambient temperature;	37%

trimethylsilyl trichloroacetate (25436-07-1) + cyclopenta-1,3-diene (542-92-7) → (+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3)

Conditions	Yield
With triphenylphosphine

5,5-bis(trimethylsilyl)cyclopentadiene (33630-76-1) → (+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3)

Conditions	Yield
Multi-step reaction with 2 steps 1: 72 percent / triethylamine / hexane / 1.) ice-cooling, 2 h, 2.) 0 - 5 deg C, 12 h 2: 37 percent / conc. H2SO4 / methanol / 18 h / Ambient temperature View Scheme

bi(cyclopentadiene) (77-73-6, 933-60-8, 1755-01-7) → (+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3)

Conditions	Yield
Multi-step reaction with 2 steps 1: 200 °C 2: triethylamine / pentane View Scheme

dicyclopentadiene (77-73-6, 933-60-8, 1755-01-7, 13257-74-4, 25850-35-5, 57429-84-2, 109428-68-4) → (+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3)

Conditions	Yield
Multi-step reaction with 2 steps 1: Heating 2: triethylamine / n-heptane; hexane / 20 °C View Scheme

(+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) → 7,7-dichloro-6-hydroxybicyclo<3.2.0>hept-2-ene (92998-64-6)

Conditions	Yield
With sodium tetrahydroborate In methanol for 21h; Ambient temperature;	96%
With lithium aluminium tetrahydride In diethyl ether for 1h; Ambient temperature;

(+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) → 7,7-dichloro-6-hydroxybicyclo<3.2.0>hept-2-ene-6-d (110097-55-7, 110171-08-9)

Conditions	Yield
With sodium borodeuteride In methanol for 15h; Ambient temperature;	95%

(+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) → 2-hydroxy-2,4,6-cycloheptatrien-1-one (533-75-5)

Conditions	Yield
With acetic acid; sodium hydroxide	95%
With sodium hydroxide; acetic acid at 130℃; for 7h; Rearrangement;	87%
With hydrogenchloride; sodium hydroxide; acetic acid for 8h; pH=1; Heating;	77%
With sodium hydroxide; acetic acid for 8h; Heating;	77%

(+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) + (R)-1-phenyl-ethyl-amine (3886-69-9) → 2-(dichloromethyl)-N-[(1R)-1-phenylethyl]cyclopent-3-ene-1-carboxamide (1192489-59-0)

Conditions	Yield
In benzene at 20℃; for 4h;	95%

(+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) → bicyclo(3.2.0)hept-2-en-6-one (925211-06-9, 925211-07-0)

Conditions	Yield
With zinc In acetic acid at 70℃; for 0.666667h;	94%
With acetic acid; zinc at 70℃; for 48h;	83%
With zinc In acetic acid	81%

2-diethylamino-4-methyl-1,3,2-dioxaphosphorinane + (+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) → Diethyl-phosphoramidic acid 7-chloro-bicyclo[3.2.0]hepta-2,6-dien-6-yl ester 3-chloro-1-methyl-propyl ester

Conditions	Yield
at 120 - 130℃; for 6h;	93%

(+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) → 5,5-dichloro-2,9-dioxatricyclo[3.2.2.03,7]nonan-3-ol

Conditions	Yield
Stage #1: (+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one With sodium tetrahydroborate Stage #2: With ozone In methanol; dichloromethane at -78℃; for 0.166667h; Stage #3: With thiourea In methanol; dichloromethane at -78 - 20℃; Further stages.;	93%

ethanol (64-17-5) + (+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) → (Z)-7,7-Dichloro-hepta-4,6-dienoic acid ethyl ester (87274-25-7)

Conditions	Yield
In benzene Irradiation; irradiation with a Hanovia 450W high-pressure mercury arc lamp;	90%

(+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) + 2-diethylamino-1,3,2-dioxaphosphorinane (38432-39-2) → Diethyl-phosphoramidic acid 7-chloro-bicyclo[3.2.0]hepta-2,6-dien-6-yl ester 3-chloro-propyl ester

Conditions	Yield
at 120 - 130℃; for 6h;	87%

(+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) + sodium methylate (124-41-4) → methyl 2-(dichloromethyl)cyclopent-3-ene-1-carboxylate (412026-46-1)

Conditions	Yield
In methanol at -5 - 0℃; for 2h;	83%

diisobutyl phosphite (1189-24-8) + (+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) → (7,7-Dichloro-6-hydroxy-bicyclo[3.2.0]hept-2-en-6-yl)-phosphonic acid diisobutyl ester (128530-26-7)

Conditions	Yield
With triethylamine In benzene Ambient temperature;	70%

dibutyl hydrogen phosphite (1809-19-4) + (+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) → (7,7-Dichloro-6-hydroxy-bicyclo[3.2.0]hept-2-en-6-yl)-phosphonic acid dibutyl ester (128530-25-6)

Conditions	Yield
With triethylamine In benzene Ambient temperature;	70%

(+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) → 7,7-dideuteriobicyclo<3.2.0>hept-2-en-6-one (51592-73-5)

Conditions	Yield
With deuteroacetic acid; zinc	67%

(+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) + di-n-propyl phosphonate (1809-21-8) → (7,7-Dichloro-6-hydroxy-bicyclo[3.2.0]hept-2-en-6-yl)-phosphonic acid dipropyl ester (128530-23-4)

Conditions	Yield
With triethylamine In benzene Ambient temperature;	67%

(+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) → (+/-)-endo-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-ol (19296-95-8, 19296-96-9, 92998-64-6, 101758-65-0, 130796-66-6, 130796-68-8)

Conditions	Yield
With sodium tetrahydroborate In methanol at 20℃; for 1.5h;	65%

(+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) + Dimethyl phosphite (868-85-9) → dimethyl 6-hydroxy-7,7-dichlorobicyclo<3.2.0>hept-2-en-6-ylphosphonate (128530-21-2)

Conditions	Yield
With triethylamine In benzene for 5h; Ambient temperature; other dialkyl phosphites;	62%
With triethylamine In benzene for 5h; Ambient temperature;	62%

2-methoxy-[1,3,2]dioxaphosphinane (31121-06-9) + (+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) → 2-(7-Chloro-bicyclo[3.2.0]hepta-2,6-dien-6-yloxy)-[1,3,2]dioxaphosphinane 2-oxide

Conditions	Yield
at 120 - 130℃; for 6h;	61%

diisopropyl hydrogenphosphonate (1809-20-7) + (+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) → (7,7-Dichloro-6-hydroxy-bicyclo[3.2.0]hept-2-en-6-yl)-phosphonic acid diisopropyl ester (128530-24-5)

Conditions	Yield
With triethylamine In benzene Ambient temperature;	60%

(+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) + phosphonic acid diethyl ester (762-04-9) → (7,7-Dichloro-6-hydroxy-bicyclo[3.2.0]hept-2-en-6-yl)-phosphonic acid diethyl ester (128530-22-3)

Conditions	Yield
With triethylamine In benzene Ambient temperature;	60%

(+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) + 4-methyl-2-methoxy-1,3,2-dioxaphosphorinane (33892-95-4) → 2-(7-chlorobicyclo<3.2.0>hepta-2,6-dien-6-yloxy)-4-methyl-1,3,2λ5-dioxaphosphorinane 2-oxide

Conditions	Yield
at 120 - 130℃; for 6h;	60%

(+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) → (+/-)-2-formylcyclopent-2-enecarboxylic acid (30758-76-0)

Conditions	Yield
With sodium hydroxide In water at 60℃; for 1h; Solvent; Temperature; Concentration; Green chemistry;	59.4%
Stage #1: (+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one With water; triethylamine In tert-butyl alcohol for 3h; Reflux; Solvolysis; Stage #2: With potassium carbonate In tert-butyl alcohol at 10℃; for 0.5h;	52%
With sodium hydrogencarbonate at 75℃; for 5h; Hydrolysis;

(+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) → C7H6Cl2O2

Conditions	Yield
With dihydrogen peroxide; sodium hydroxide In methanol; water at -5 - 30℃;	57%

1,3,2-dioxaphosphinan-2-oxide (16352-21-9) + (+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) → 2-(7,7-dichloro-6-hydroxybicyclo<3.2.0>hept-2-en-6-yl)-1,3,2-dioxaphosphorinane 2-oxide

Conditions	Yield
With triethylamine In benzene for 12h;	55%

4-methyl-[1,3,2]dioxaphosphinane 2-oxide (16368-20-0) + (+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) → 2-(7,7-Dichloro-bicyclo[3.2.0]hept-2-en-6-yloxy)-4-methyl-[1,3,2]dioxaphosphinane 2-oxide

Conditions	Yield
With triethylamine In benzene for 12h;	55%

(+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one (5307-99-3) + (R)-1-phenyl-ethyl-amine (3886-69-9) → (3R,3aS,6aR)-3-hydroxy-2-[(1R)-1-phenylethyl]-3,3a,6,6a-tetrahydrocyclopenta[c]pyrrol-1(2H)-one (1040919-29-6) + (3S,3aR,6aS)-3-hydroxy-2-[(1R)-1-phenylethyl]-3,3a,6,6a-tetrahydrocyclopenta[c]pyrrol-1(2H)-one (1040919-30-9)

Conditions	Yield
Stage #1: (+/-)-7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one; (R)-1-phenyl-ethyl-amine In benzene at 20℃; for 4h; Stage #2: With barium(II) oxide In water; acetonitrile for 20h; Reflux;	A 47% B 46%

Upstream product

• 25436-07-1 trimethylsilyl trichloroacetate 
• 542-92-7 cyclopenta-1,3-diene 
• 79-36-7 dichloroacethyl chloride 
• 20618-08-0 β,β-dichloroacryloyl chloride 
• 78133-61-6 7,7-dichloro-2,4-exo-bis(trimethylsilyl)bicyclo<3.2.0>hept-2-en-6-one 
• 76-02-8 trifluoroacetyl chloride 
• 33630-76-1 5,5-bis(trimethylsilyl)cyclopentadiene 
• 4342-33-0 tributyl(trichloroacetoxy)stannane 
• 77-73-6 dicyclopentadiene 
• 4591-28-0 dichloroketene 
• 63320-25-2 7,7-dichloro-4β-trimethylsilylbicyclo<3.2.0>hept-2-en-6-one 
• 50-00-0 formaldehyd 
• 77-73-6 bi(cyclopentadiene) 

Downstream Products

• 92998-64-6 7,7-dichloro-6-hydroxybicyclo<3.2.0>hept-2-ene 
• 140669-25-6 Benzoic acid 6-chloro-7-oxo-bicyclo[3.2.0]hept-3-en-1-yl ester 
• 533-75-5 2-hydroxy-2,4,6-cycloheptatrien-1-one 
• 19296-95-8 (1R,5S,6R)-7,7-Dichloro-bicyclo[3.2.0]hept-2-en-6-ol 
• 1192489-59-0 2-(dichloromethyl)-N-[(1R)-1-phenylethyl]cyclopent-3-ene-1-carboxamide 
• 1040919-29-6 (3R,3aS,6aR)-3-hydroxy-2-[(1R)-1-phenylethyl]-3,3a,6,6a-tetrahydrocyclopenta[c]pyrrol-1(2H)-one 
• 1040919-30-9 (3S,3aR,6aS)-3-hydroxy-2-[(1R)-1-phenylethyl]-3,3a,6,6a-tetrahydrocyclopenta[c]pyrrol-1(2H)-one 
• 38754-71-1 (3aR,4R,5R,6aS)-4-formyl-2-oxohexahydro-2H-cyclopenta[b]furan-5-yl biphenyl-4-carboxylate 
• 54324-79-7 (3aR,4R,5R,6aS)-4-((E)-4-(3-chlorophenoxy)-3-oxobut-1-enyl)-2-oxohexahydro-2H-cyclopenta[b]furan-5-yl [1,1′-biphenyl]-4-carboxylate 
• 41639-72-9 (1S,5R,6R,7R)-6-(3-oxo-5-phenyl-1E-pentenyl)-7-<(4-phenylbenzoyl)oxy>-2-oxabicyclo<3.3.0>octan-3-one 
• 31753-00-1 [1,1'-bisphenyl]-4-carboxylic acid (3aR,4R,5R,6aS)-hexahydro-2-oxo-4-[(1E)-3-oxo-1-octen-1-yl]-2H-cyclopenta[b]furan-5-yl ester 
• 54142-64-2 [1,1'-biphenyl]-4-carboxylic acid (3aR,4R,5R,6aS)-hexahydro-2-oxo-4-[(1E)-3-oxo-4-[3-(trifluoromethyl)phenoxy]-1-buten-1-yl]-2H-cyclopenta[b]furan-5-yl ester 
• 54713-44-9 (3aR,4R,5R,6aS)-4-((R,E)-4-(3-chlorophenoxy)-3-hydroxybut-1-enyl)-2-oxohexahydro-2H-cyclopenta[b]furan-5-yl[1,1′-biphenyl]-4-carboxylate 
• 54294-93-8 Biphenyl-4-carboxylic acid (3aR,4R,5R,6aS)-4-[(E)-(S)-4-(3-chloro-phenoxy)-3-hydroxy-but-1-enyl]-2-oxo-hexahydro-cyclopenta[b]furan-5-yl ester 

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