7686-77-3

Basic information

• Product Name: 3-Cyclopentene-1-carboxylic acid
• Synonyms: CYCLOPENT-3-ENE-1-CARBOXYLIC ACID;CYCLOPENT-3-ENECARBOXYLIC ACID;3-CYCLOPENTENE-1-CARBOXYLIC ACID;3-CYCLOPENTENECARBOXYLIC ACID;TIMTEC-BB SBB008010;Cyclopentene-1-CarboxylicAcid;3-Cyclopentene-1-carboxylic acid (7CI,8CI,9CI);3-Cyclopentenecarboxylic
• CAS NO: 7686-77-3
• Molecular Formula: C₆H₈O₂
• Molecular Weight: 112.13
• EINECS: 236-047-0
• Product Categories: ACIDHALIDE;pharmacetical;INTERMEDIATESOFDOLASETRONMESYLATE;Carboxylic Acids;Organic acids;API intermediates;Carboxylic Acids;Ring Systems;C6;Carbonyl Compounds;Building Blocks;Carbonyl Compounds;Chemical Synthesis;Organic Building Blocks
• Mol File: 7686-77-3.mol
• Article Data: 18

Chemical Properties

• Boiling Point: 215 °C(lit.)
• Flash Point: >230 °F
• Appearance: Clear colorless to slightly yellow liquid
• Density: 1.084 g/mL at 25 °C(lit.)
• Vapor Pressure: 0.0282mmHg at 25°C
• Refractive Index: n20/D 1.469(lit.)
• Storage Temp.: Refrigerator (+4°C)
• PKA: 4.62±0.20(Predicted)
• CAS DataBase Reference: 3-Cyclopentene-1-carboxylic acid(CAS DataBase Reference)
• NIST Chemistry Reference: 3-Cyclopentene-1-carboxylic acid(7686-77-3)
• EPA Substance Registry System: 3-Cyclopentene-1-carboxylic acid(7686-77-3)

Safety Data

• Hazard Codes: Xi
• Statements: 36/37/38
• Safety Statements: 24/25-36-26
• RIDADR: 3265
• WGK Germany: 3
• HazardClass: 8
• PackingGroup: III
• Hazardous Substances Data: 7686-77-3(Hazardous Substances Data)

Usage

Chemical Properties

Clear colorless to slightly yellow liquid

Uses

3-Cyclopentene-1-carboxylic acid is used as an intermediate in the production of dolasetron mesylate.

InChI:InChI=1/C6H8O2/c7-6(8)5-3-1-2-4-5/h1-2,5H,3-4H2,(H,7,8)/p-1

Synthetic route

Dimethyl 3-cyclopentene-1,1-dicarboxylate (88326-51-6) → 3-cyclopentene-1-carboxylic acid (7686-77-3)

Conditions	Yield
at 185 - 195℃; for 1h;	100%
at 180℃; for 1h; Neat (no solvent);	93%
at 170 - 175℃; for 2h;	89%

2-allyl-4-pentenoic acid (99-67-2) → 3-cyclopentene-1-carboxylic acid (7686-77-3)

Conditions	Yield
With tricyclohexylphosphine[1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidine][benzylidene]ruthenium(II) dichloride In dichloromethane at 40℃; for 1h; Schlenk technique;	98%

methyl cyclopent-3-ene-1-carboxylate (58101-60-3) → 3-cyclopentene-1-carboxylic acid (7686-77-3)

Conditions	Yield
With water; lithium hydroxide In tetrahydrofuran at 25℃; for 15h;	90%

Dimethyl 3-cyclopentene-1,1-dicarboxylate (84646-68-4) → 3-cyclopentene-1-carboxylic acid (7686-77-3)

Conditions	Yield
Stage #1: Dimethyl 3-cyclopentene-1,1-dicarboxylate With water; potassium hydroxide In ethanol at 45℃; for 14h; Inert atmosphere; Stage #2: at 180℃; for 1h; Inert atmosphere;	73%
Multi-step reaction with 2 steps 1: 45percent KOH / aq. ethanol / 15 h / Heating 2: 100 percent / 1 h / 185 - 195 °C View Scheme
Multi-step reaction with 2 steps 1: water; potassium hydroxide / ethanol / 1 h / Reflux 2: 1 h / 180 °C / Neat (no solvent) View Scheme

methyl cyclopent-3-ene-1-carboxylate (58101-60-3) + acetonitrile (75-05-8) → 3-cyclopentene-1-carboxylic acid (7686-77-3) + 3-(cyclopent-3-en-1-yl)-3-oxopropanenitrile (97820-85-4)

Conditions	Yield
With potassium tert-butylate; isopropyl alcohol In 2-methyltetrahydrofuran at 20℃; for 2h; Inert atmosphere;	A n/a B 29%

(+/-)-cyclopent-2-enecarboxylic acid (67886-24-2, 67886-30-0, 77983-99-4, 2348-89-2) + methyl iodide (74-88-4) → 3-cyclopentene-1-carboxylic acid (7686-77-3) + cis-3-methylcyclopentanecarboxylic acid (6240-43-3, 6240-44-4, 24070-68-6) + acide methyl-2 cyclopentanecarboxylique-1 cis (4541-43-9, 5454-78-4, 18335-62-1, 97276-84-1, 109716-77-0, 109716-78-1, 134877-06-8)

Conditions	Yield
With pyridine; bis(1,5-cyclooctadiene)nickel (0); sulfuric acid 1) THF, room temperature, 24 h, 2) THF, room temperature, 24 h; Yield given. Multistep reaction;	A 10% B n/a C 4%

carbon dioxide (124-38-9) + cyclopent-3-enyl bromide (1781-66-4) → 3-cyclopentene-1-carboxylic acid (7686-77-3)

Conditions	Yield
(i) Mg, Et2O, (ii) /BRN= 1900390/; Multistep reaction;
With magnesium 1.) ether, RT, 5 h; Yield given. Multistep reaction;

diethyl 2-vinylcyclopropane-1,1-dicarboxylate (7686-78-4) → 3-cyclopentene-1-carboxylic acid (7686-77-3)

Conditions	Yield
Heating;
Multi-step reaction with 3 steps 1: 94 percent / 480 °C 2: KOH / H2O; ethanol / 6 h / Heating 3: 180 °C View Scheme

cyclopent-3-ene-1-carbonitrile (4492-41-5) → 3-cyclopentene-1-carboxylic acid (7686-77-3)

Conditions	Yield
With sodium hydroxide

cyclopentene-(3)-carbaldehyde-(1) → 3-cyclopentene-1-carboxylic acid (7686-77-3)

Conditions	Yield
With barium dihydroxide; water; silver(l) oxide
With sodium hydroxide at 350℃;

Cyclopent-3-ene-1,1-dicarboxylic acid diethyl ester (21622-00-4) → 3-cyclopentene-1-carboxylic acid (7686-77-3)

Conditions	Yield
Multi-step reaction with 2 steps 1: KOH / H2O; ethanol / 6 h / Heating 2: 180 °C View Scheme

cyclopent-3-enol (14320-38-8) → 3-cyclopentene-1-carboxylic acid (7686-77-3)

Conditions	Yield
Multi-step reaction with 2 steps 1: (i) TsCl, Py, (ii) /BRN= 3587243/ 2: aq. NaOH View Scheme

diallylmalonic acid diethyl ester (3195-24-2) → 3-cyclopentene-1-carboxylic acid (7686-77-3)

Conditions	Yield
Multi-step reaction with 3 steps 1: water; potassium hydroxide / ethanol / 4 h / Reflux 2: neat (no solvent) / 3 h / 140 °C / Microwave irradiation 3: tricyclohexylphosphine[1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidine][benzylidene]ruthenium(II) dichloride / dichloromethane / 1 h / 40 °C / Schlenk technique View Scheme

2,2-diallylmalonic acid (4372-31-0) → 3-cyclopentene-1-carboxylic acid (7686-77-3)

Conditions	Yield
Multi-step reaction with 2 steps 1: neat (no solvent) / 3 h / 140 °C / Microwave irradiation 2: tricyclohexylphosphine[1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidine][benzylidene]ruthenium(II) dichloride / dichloromethane / 1 h / 40 °C / Schlenk technique View Scheme

3-cyclopentene-1-carboxylic acid (7686-77-3) + methyl iodide (74-88-4) → 1-Methylcyclopent-3-ene-1-carboxylic acid (124346-92-5)

Conditions	Yield
Stage #1: 3-cyclopentene-1-carboxylic acid With lithium diisopropyl amide In tetrahydrofuran; n-heptane; ethylbenzene at -30 - 25℃; for 15h; Stage #2: methyl iodide In tetrahydrofuran; n-heptane; ethylbenzene at -30 - 25℃; for 2h;	100%
Stage #1: 3-cyclopentene-1-carboxylic acid With lithium diisopropyl amide In tetrahydrofuran; hexane at -78 - 20℃; for 12h; Inert atmosphere; Stage #2: methyl iodide In tetrahydrofuran; hexane at -40 - 20℃; for 18h; Inert atmosphere;	87%
Stage #1: 3-cyclopentene-1-carboxylic acid With tert.-butyl lithium In tetrahydrofuran at -78℃; for 1.5h; Inert atmosphere; Stage #2: methyl iodide In tetrahydrofuran at -78℃;	70%

methanol (67-56-1) + 3-cyclopentene-1-carboxylic acid (7686-77-3) → methyl cyclopent-3-ene-1-carboxylate (58101-60-3)

Conditions	Yield
Stage #1: 3-cyclopentene-1-carboxylic acid With 1,1'-carbonyldiimidazole In dichloromethane at 0 - 20℃; for 4h; Stage #2: methanol In dichloromethane	99%
With oxalyl dichloride In dichloromethane; N,N-dimethyl-formamide	85%
With sulfuric acid at 0 - 80℃; for 6h;	80%

3-cyclopentene-1-carboxylic acid (7686-77-3) → cyclopentanecarboxylic acid (3400-45-1)

Conditions	Yield
With palladium diacetate; 4,4,5,5-tetramethyl-[1,3,2]-dioxaboralane In dichloromethane at 25℃; for 12h; Schlenk technique; Inert atmosphere;	99%
With palladium diacetate; 4,4,5,5-tetramethyl-[1,3,2]-dioxaboralane In dichloromethane at 25℃; for 12h; Sealed tube; Inert atmosphere; chemoselective reaction;	99%

3-cyclopentene-1-carboxylic acid (7686-77-3) → 4-(hydroxymethyl)cyclopentene (25125-21-7)

Conditions	Yield
With lithium aluminium tetrahydride In tetrahydrofuran at 23℃; for 0.5h;	98%
With lithium aluminium tetrahydride In diethyl ether for 6h; Heating;	97%
With lithium aluminium tetrahydride In tetrahydrofuran at 66℃; for 6h; Reduction;	95%

3-cyclopentene-1-carboxylic acid (7686-77-3) → (3S*,4S*)-3,4-dibromocyclopentanecarboxylic acid (89415-65-6, 140451-75-8)

Conditions	Yield
With Oxalyl bromide; dimethyl sulfoxide In dichloromethane at -10 - 20℃; Inert atmosphere; stereoselective reaction;	96%
With hydrogen bromide; dimethyl sulfoxide In chloroform; water at 65℃; for 12h;	61%
With bromine In cyclohexane

3-cyclopentene-1-carboxylic acid (7686-77-3) + N,O-dimethylhydroxylamine*hydrochloride (6638-79-5) → cyclopent-3-enecarboxylic acid methoxy-methyl-amide (248275-70-9)

Conditions	Yield
Stage #1: 3-cyclopentene-1-carboxylic acid With 1,1'-carbonyldiimidazole In dichloromethane for 0.75h; Stage #2: N,O-dimethylhydroxylamine*hydrochloride In dichloromethane	96%
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In dichloromethane at 20℃; Inert atmosphere;	71%
Stage #1: 3-cyclopentene-1-carboxylic acid With 1,1'-carbonyldiimidazole In dichloromethane at 0℃; for 0.5h; Inert atmosphere; Sealed tube; Stage #2: N,O-dimethylhydroxylamine*hydrochloride In dichloromethane at 0 - 20℃; Inert atmosphere; Sealed tube;

3-cyclopentene-1-carboxylic acid (7686-77-3) + methyl iodide (74-88-4) → methyl cyclopent-3-ene-1-carboxylate (58101-60-3)

Conditions	Yield
With potassium carbonate In DMF (N,N-dimethyl-formamide) at 20℃; for 16h;	96%
With potassium carbonate In N,N-dimethyl-formamide at 20℃; for 16h;	96%
With potassium carbonate In DMF (N,N-dimethyl-formamide) at 20℃; for 16h;	96%
With potassium carbonate In N,N-dimethyl-formamide at 20℃; for 16h; Schlenk technique; Inert atmosphere;	87%
With potassium carbonate In N,N-dimethyl-formamide at 20℃; for 16h;	86%

3-cyclopentene-1-carboxylic acid (7686-77-3) + hexan-1-ol (111-27-3) → hexyl 3-cyclopentene-1-carboxylate

Conditions	Yield
With glucose-diphenylaminium tosylate-derived carbon solid acid (GDTCSA) In n-heptane at 80℃; for 5h;	96%

3-cyclopentene-1-carboxylic acid (7686-77-3) → (1RS,4SR,6RS)-6-bromo-2-oxabicyclo<2.2.1>heptan-3-one (130505-94-1)

Conditions	Yield
With trimethylsilyl bromide; N-ethyl-N,N-diisopropylamine In 1,4-dioxane; dimethyl sulfoxide for 12h; Heating;	95%
With trimethylsilyl bromide; dimethyl sulfoxide; N-ethyl-N,N-diisopropylamine In chloroform for 12h; Heating;	40%
With trimethylsilyl bromide; dimethyl sulfoxide; N-ethyl-N,N-diisopropylamine In chloroform for 12h; Heating;	40%

3-cyclopentene-1-carboxylic acid (7686-77-3) + benzyl bromide (100-39-0) → benzyl cyclopent‐3‐ene‐1‐carboxylate (130762-09-3)

Conditions	Yield
With potassium carbonate In acetone at 60℃; for 2h;	95%
With potassium carbonate In N,N-dimethyl-formamide at 20℃;	94%
With tetra-(n-butyl)ammonium iodide; sodium hydrogencarbonate In dichloromethane; water at 20℃; for 16h;	70%

3-cyclopentene-1-carboxylic acid (7686-77-3) + BnBr (22393-62-0) → benzyl cyclopent‐3‐ene‐1‐carboxylate (130762-09-3)

Conditions	Yield
With potassium carbonate In [(2)H6]acetone; ethyl acetate; Petroleum ether	95%

3-cyclopentene-1-carboxylic acid (7686-77-3) + (E)-(5-bromopent-3-en-1-yl)benzene (129413-75-8, 138847-69-5) → (E)-1-(5-phenylpent-2-en-1-yl)cyclopent-3-ene-1-carboxylic acid

Conditions	Yield
Stage #1: 3-cyclopentene-1-carboxylic acid With lithium diisopropyl amide In tetrahydrofuran; hexane at -78 - 20℃; Inert atmosphere; Stage #2: (E)-(5-bromopent-3-en-1-yl)benzene In tetrahydrofuran; hexane at -40 - 20℃; Inert atmosphere;	92%

3-cyclopentene-1-carboxylic acid (7686-77-3) + 1-methyl-1-phenylethyl 2,2,2-trichloroacetimidoate (147221-33-8) → 2-phenylpropan-2-yl cyclopent-3-enecarboxylate (1105703-39-6)

Conditions	Yield
In dichloromethane; cyclohexane at 20℃; for 16h;	90%

ethanol (64-17-5) + 3-cyclopentene-1-carboxylic acid (7686-77-3) → ethyl 3-cyclopentene-1-carboxylate (21622-01-5)

Conditions	Yield
With thionyl chloride at 5 - 20℃; for 1.5h;	89.42%
With thionyl chloride at 5 - 20℃; for 0.5h;	84%
With thionyl chloride at -10℃; for 4h; Inert atmosphere; Schlenk technique; Reflux;	80%
With thionyl chloride at 0 - 20℃;	54%
With thionyl chloride at 10 - 35℃;

2-methyl-3-bromo-1-propene (1458-98-6) + 3-cyclopentene-1-carboxylic acid (7686-77-3) → 1-(2-methylallyl)cyclopent-3-ene-1-carboxylic acid

Conditions	Yield
Stage #1: 3-cyclopentene-1-carboxylic acid With lithium diisopropyl amide In tetrahydrofuran; hexane at -78 - 20℃; Inert atmosphere; Stage #2: 2-methyl-3-bromo-1-propene In tetrahydrofuran; hexane at -40 - 20℃; Inert atmosphere;	89%

3-cyclopentene-1-carboxylic acid (7686-77-3) + 3-amino-6-bromo-isothiazolo[4,3-b]pyridine → N-(6-bromo-isothiazolo[4,3-b]pyridin-3-yl)cyclopent-3-enecarboxamide

Conditions	Yield
With N-ethyl-N,N-diisopropylamine; N-[(dimethylamino)-3-oxo-1H-1,2,3-triazolo[4,5-b]pyridin-1-yl-methylene]-N-methylmethanaminium hexafluorophosphate In N,N-dimethyl-formamide at 20℃;	89%

1-iodo-3-chloro-propane (6940-76-7) + 3-cyclopentene-1-carboxylic acid (7686-77-3) → 1-(3-chloropropyl)cyclopent-3-ene-1-carboxylic acid

Conditions	Yield
Stage #1: 3-cyclopentene-1-carboxylic acid With n-butyllithium; diisopropylamine In tetrahydrofuran; hexane at -10 - 20℃; for 2h; Inert atmosphere; Stage #2: 1-iodo-3-chloro-propane In tetrahydrofuran at -10 - 0℃; for 0.5h; Inert atmosphere;	89%
Stage #1: 3-cyclopentene-1-carboxylic acid With n-butyllithium; diisopropylamine In tetrahydrofuran; hexane at -20 - 20℃; Stage #2: 1-iodo-3-chloro-propane In tetrahydrofuran; hexane at -20 - 20℃;

2-Naphthalenemethanol (1592-38-7) + 3-cyclopentene-1-carboxylic acid (7686-77-3) → naphthalen-2-ylmethyl cyclopent-3-enecarboxylate

Conditions	Yield
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In dichloromethane at 0 - 20℃; Inert atmosphere;	88%

3-cyclopentene-1-carboxylic acid (7686-77-3) + aniline (62-53-3) → 3-cyclopentenecarboxylic acid phenyl amide (7686-79-5)

Conditions	Yield
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In N,N-dimethyl-formamide at 0 - 20℃; Inert atmosphere;	87%
Stage #1: 3-cyclopentene-1-carboxylic acid With oxalyl dichloride; N,N-dimethyl-formamide In dichloromethane at 20℃; for 1h; Stage #2: aniline With dmap In dichloromethane at 20℃; for 16h;

N-hydroxyphthalimide + 3-cyclopentene-1-carboxylic acid (7686-77-3) → 1,3-dioxoisoindolin-2-yl cyclopent-3-ene-1-carboxylate

Conditions	Yield
With dmap; diisopropyl-carbodiimide In DClO4 for 12h; Inert atmosphere;	86%
With dmap; diisopropyl-carbodiimide In dichloromethane for 1h;	60%
With dmap; diisopropyl-carbodiimide In dichloromethane at 20℃;	46%

3-cyclopentene-1-carboxylic acid (7686-77-3) → cyclopent-3-ene-1-carboxylic acid chloride (3744-80-7)

Conditions	Yield
With thionyl chloride Heating;	85%
With oxalyl dichloride; N,N-dimethyl-formamide In dichloromethane at 0 - 20℃; for 5h; Chlorination;	80%
With thionyl chloride

3-cyclopentene-1-carboxylic acid (7686-77-3) → trans-3,4-dichlorocyclopentanecarboxylic acid

Conditions	Yield
With oxalyl dichloride; 1,1'-sulfinylbisbenzene In dichloromethane at -78 - 20℃; for 1h; Inert atmosphere;	85%

3-cyclopentene-1-carboxylic acid (7686-77-3) + isobutene (115-11-7) → tert-butyl cyclopent-3-ene-1-carboxylate (84694-13-3)

Conditions	Yield
With sulfuric acid In diethyl ether for 96h; Ambient temperature;	84%
With sulfuric acid In diethyl ether at -78 - 20℃; for 96h; Sealed tube;	16.98 g

3-cyclopentene-1-carboxylic acid (7686-77-3) + N,N-dimethylethylenediamine (108-00-9) → C10H17NO2

Conditions	Yield
Stage #1: 3-cyclopentene-1-carboxylic acid With 4-methyl-morpholine In tetrahydrofuran at 0℃; for 0.166667h; Stage #2: With isobutyl chloroformate In tetrahydrofuran for 0.25h; Stage #3: N,N-dimethylethylenediamine In tetrahydrofuran for 2h;	84%

3-cyclopentene-1-carboxylic acid (7686-77-3) + tert-butyl alcohol (75-65-0) → tert-butyl cyclopent-3-ene-1-carboxylate (84694-13-3)

Conditions	Yield
Stage #1: 3-cyclopentene-1-carboxylic acid With oxalyl dichloride In dichloromethane; N,N-dimethyl-formamide at 5 - 20℃; Stage #2: tert-butyl alcohol With triethylamine In dichloromethane at 5 - 20℃;	83%

3-cyclopentene-1-carboxylic acid (7686-77-3) + N-ethyl-N-phenylamine (103-69-5) → N-ethyl-N-phenylcyclopent-3-ene-1-carboxamide

Conditions	Yield
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In dichloromethane at 20℃; Inert atmosphere;	83%

3-cyclopentene-1-carboxylic acid (7686-77-3) + isopropyl alcohol (67-63-0) → isopropyl cyclopent-3-ene-1-carboxylate

Conditions	Yield
With thionyl chloride at 0℃; for 5h; Inert atmosphere; Reflux;	82%

Upstream product

• 88326-51-6 Dimethyl 3-cyclopentene-1,1-dicarboxylate 
• 124-38-9 carbon dioxide 
• 1781-66-4 cyclopent-3-enyl bromide 
• 7686-78-4 diethyl 2-vinylcyclopropane-1,1-dicarboxylate 
• 21622-00-4 Cyclopent-3-ene-1,1-dicarboxylic acid diethyl ester 
• 58101-60-3 methyl cyclopent-3-ene-1-carboxylate 
• 75-05-8 acetonitrile 
• 4372-31-0 2,2-diallylmalonic acid 
• 3195-24-2 diallylmalonic acid diethyl ester 
• 99-67-2 2-allyl-4-pentenoic acid 
• 14320-38-8 cyclopent-3-enol 
• 84646-68-4 Dimethyl 3-cyclopentene-1,1-dicarboxylate 
• 4492-41-5 cyclopent-3-ene-1-carbonitrile 
• 67886-24-2 (+/-)-cyclopent-2-enecarboxylic acid 

Downstream Products

• 5732-97-8 (1S,4R)-2-Oxa-bicyclo[2.2.1]heptan-3-one 
• 170708-34-6 N-(benzyloxycarbonyl)cyclopent-3-enylamine 
• 58101-60-3 methyl cyclopent-3-ene-1-carboxylate 
• 915098-60-1 cyclopent-3-enecarboxylic acid tert-butyldiphenylsilyl ester 
• 852364-14-8 Toluene-4-sulfonic acid (1S,3S,5R)-1-(6-oxa-bicyclo[3.1.0]hex-3-yl)methyl ester 
• 7686-79-5 3-cyclopentenecarboxylic acid phenyl amide 
• 18593-39-0 Δ³-Cyclopentenylmethyl-p-brom-benzolsulfonat 
• 1004764-72-0 benzyl {2-[4-(3-chloropropoxy)phenyl]-5,6-dihydro-4H-cyclopenta[d][1,3]thiazol-5-yl}carbamate 
• 1004764-73-1 benzyl (2-{4-[3-(2-methylpyrrolidin-1-yl)propoxy]phenyl}-5,6-dihydro-4H-cyclopenta[d][1,3]thiazol-5-yl)carbamate 
• 1355328-26-5 benzyl bicyclo[3.1.0]hexan-3-ylcarbamate 
• 946152-80-3 (1R,3R)-3-hydroxy-cyclopentanecarboxylic acid benzyl ester 
• 916736-76-0 benzyl 3-hydroxycyclopentanecarboxylate 
• 1443511-42-9 (S)-1-tert-butyl 2-((1R,3R)-3-((R)-1-((S)-4-(4-chlorophenyl)-4-hydroxy-3,3-dimethylpiperidin-1-yl)-3-methyl-1-oxobutan-2-ylcarbamoyl)cyclopentyl) pyrrolidine-1,2-dicarboxylate 
• 946594-19-0 BMS-457 

Relevant articles and documents

A green, economical synthesis of β-ketonitriles and trifunctionalized building blocks from esters and lactones

The acylation of the acetonitrile anion with lactones and esters in ethereal solvents was successfully exploited using inexpensive KOt-Bu to obtain a variety of β-ketonitriles and trifunctionalized building blocks, including useful O-unprotected diols. It was discovered that lactones react to produce the corresponding derivatized cyclic hemiketals. Furthermore, the addition of a catalytic amount of isopropanol, or 18-crown-6, was necessary to facilitate the reaction and to reduce side-product formation under ambient conditions.

Enantioselective desymmetrization via carbonyl-directed catalytic asymmetric hydroboration and Suzuki-Miyaura cross-coupling

The rhodium-catalyzed enantioselective desymmetrization of symmetric γ,δ-unsaturated amides via carbonyl-directed catalytic asymmetric hydroboration (directed CAHB) affords chiral secondary organoboronates with up to 98% ee. The chiral γ-borylated products undergo palladium-catalyzed Suzuki-Miyaura cross-coupling via the trifluoroborate salt with stereoretention.