60176-77-4

Basic information

• Product Name: (1R,4S)-CIS-4-ACETOXY-2-CYCLOPENTEN-1-OL
• Synonyms: (1S,4R)-CIS-4-HYDROXY-2-CYCLOPENTENYL ACETATE;(1R,4S)-CIS-4-ACETOXY-2-CYCLOPENTEN-1-OL;(1S,4R)-4-HYDROXYCYCLOPENT-2-ENYL ACETATE
• CAS NO: 60176-77-4
• Molecular Formula: C₇H₁₀O₃
• Molecular Weight: 142.15
• Mol File: 60176-77-4.mol
• Article Data: 40

Chemical Properties

• Melting Point: 49-51 °C
• Boiling Point: 207.984 °C at 760 mmHg
• Flash Point: 83.718 °C
• Appearance: /
• Density: 1.171 g/cm³
• Storage Temp.: Store at +2°C to +8°C.
• CAS DataBase Reference: (1R,4S)-CIS-4-ACETOXY-2-CYCLOPENTEN-1-OL(CAS DataBase Reference)
• NIST Chemistry Reference: (1R,4S)-CIS-4-ACETOXY-2-CYCLOPENTEN-1-OL(60176-77-4)
• EPA Substance Registry System: (1R,4S)-CIS-4-ACETOXY-2-CYCLOPENTEN-1-OL(60176-77-4)

Safety Data

• Safety Statements: 22-24/25
• WGK Germany: 3
• F: 10
• Hazardous Substances Data: 60176-77-4(Hazardous Substances Data)

Usage

Uses

(1R,4S)-cis-4-Acetoxy-2-cyclopenten-1-ol can be used as a reactant in the total synthesis of Bartlett′s brefeldin intermediate, spinosyn A analogs, (+)-7-deaza-5′-noraristeromycin, (±) strychnine and the Wieland-Gumlich aldehyde.

InChI:InChI=1S/C7H10O3/c1-5(8)10-7-3-2-6(9)4-7/h2-3,6-7,9H,4H2,1H3/t6-,7+/m1/s1

Synthetic route

cis-1,4-diacetoxy-2-cyclopentene (54664-61-8) → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + (1R,4S)-4-hydroxy-2-cyclopentene-1-yl acetate (60410-16-4)

Conditions	Yield
With methanol; lipase B from Candida antarctica In tert-butyl methyl ether at 5℃; for 16h; Enzymatic reaction; enantioselective reaction;	A n/a B 95%
With sodium hydroxide; Esterase(porcine liver)PLE In water at 32℃; for 8h; Product distribution; further enzymes; pH=7, phosphate buffer;
With N-(2-acetamido)-2-aminoethanesulfonic acid; ethanolamine; 2-amino-2-hydroxymethyl-1,3-propanediol at 37℃; for 8h; Product distribution; antibody of IgG class: 37E8, pH 8.0; Km, Kcat, Ki; var. enzymes and time;

cis-1,4-diacetoxy-2-cyclopentene (54664-61-8) → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

Conditions	Yield
With sodium hydroxide; phosphate buffer; immobilized porcine liver esterase (PLE, E. C. 3.1.1.1) on Eupergit C at 32℃; for 14h; pH= 7;	87%
With sodium hydroxide; sodium phosphate buffer; Trichosporon beigelii (NCIM 3326) In ethanol for 26h; pH=7; Hydrolysis;	74%
With Trichosporon beigelii NCIM 3326 In ethanol at 20℃; for 26h; pH=7; aq. phosphate buffer; Enzymatic reaction; optical yield given as %ee;	74%

vinyl acetate (108-05-4) + cis-4-cyclopentene-1,3-diol (29783-26-4) → cis-1,4-diacetoxy-2-cyclopentene (54664-61-8) + (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

Conditions	Yield
With triethylamine In tetrahydrofuran for 4h; Ambient temperature; lipase from Mucor sp.;	A 10% B 78%
With Chirazyme In acetic acid butyl ester for 12h;	A 72% B 22%
With triethylamine In tetrahydrofuran for 2.5h; Ambient temperature; pancreatin;	A 32% B 65%

(1R,3S)-(-)-1-acetoxycyclopentan-3-ol (103729-50-6) → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

Conditions	Yield
With tetrabutyl ammonium fluoride; triethylamine In tetrahydrofuran	77%
With tetrabutyl ammonium fluoride; triethylamine In tetrahydrofuran for 2h; Ambient temperature;	67%
With tetrabutyl ammonium fluoride; triethylamine In tetrahydrofuran Inert atmosphere;	50%

vinyl acetate (108-05-4) + cis-4-cyclopentene-1,3-diol → cis-1,4-diacetoxy-2-cyclopentene (54664-61-8) + (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + (1R,4S)-4-hydroxy-2-cyclopentene-1-yl acetate (60410-16-4)

Conditions	Yield
lipase EC 3.1.1.3 L10 In water; acetone at 5 - 25℃; for 6.5h; Product distribution / selectivity;	A n/a B 76.4% C n/a
lipase EC 3.1.1.3 QLC In water; acetone at 5 - 25℃; for 6.5h; Product distribution / selectivity;	A n/a B 76.4% C n/a
lipase EC 3.1.1.3 QL In water; acetone at 5 - 25℃; for 6.5h; Product distribution / selectivity;	A n/a B 75.5% C n/a
lipase EC 3.1.1.3 QLG In water; acetone at 5 - 25℃; for 6.5h; Product distribution / selectivity;	A n/a B 61.9% C n/a
pancreatin lipase In water; acetone at 5 - 25℃; for 6.5h; Product distribution / selectivity;	A n/a B 16.5% C n/a

cis-3,5-diacetoxycyclopentene → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

Conditions	Yield
With pig liver esterase; sodium hydroxide In aq. phosphate buffer for 19h; pH=7; Enzymatic reaction;	75%

vinyl acetate (108-05-4) + cis-4-cyclopentene-1,3-diol (29783-26-4) → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

Conditions	Yield
With Pancreatin; triethylamine In tetrahydrofuran at 20℃; for 3h;	72%
With Pancreatin	72%
With Pancreatin; triethylamine In tetrahydrofuran; water at 5℃; for 23h;	70%

vinyl acetate (108-05-4) + cis-4-cyclopentene-1,3-diol (29783-26-4) → cis-1,4-diacetoxy-2-cyclopentene (54664-61-8) + (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + (1R,4S)-4-hydroxy-2-cyclopentene-1-yl acetate (60410-16-4)

Conditions	Yield
With triethylamine In tetrahydrofuran at 20℃; for 23h; Enzymatic reaction; enantioselective reaction;	A 25% B 61% C n/a

vinyl acetate (108-05-4) + cis-cyclopent-4-ene-1,3-diol → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

Conditions	Yield
With triethylamine In tetrahydrofuran at 20℃; for 22h; Enzymatic reaction;	53%

Isopropenyl acetate (108-22-5) + cis-4-cyclopentene-1,3-diol (29783-26-4) → cis-1,4-diacetoxy-2-cyclopentene (54664-61-8) + (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

Conditions	Yield
In various solvent(s) at 50℃; for 72h; Candida antarctica lipase B (Novo SP-435); other meso-diols; enzymatic asymmetrization of meso-2-cycloalken-1,4-diols in organic media;	A n/a B 52%
In various solvent(s) at 50℃; for 72h; Candida antarctica lipase B (Novo SP-435); Yields of byproduct given;	A n/a B 52%

Isopropenyl acetate (108-22-5) + cis-4-cyclopentene-1,3-diol (29783-26-4) → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

Conditions	Yield
at 50℃; acrylic supported Candida antarctica lipase B;	50%

2,2,2-trichloroethyl acetate (625-24-1) + cis-4-cyclopentene-1,3-diol (29783-26-4) → cis-1,4-diacetoxy-2-cyclopentene (54664-61-8) + (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

Conditions	Yield
In pyridine for 72h; Ambient temperature; porcine pancreatic lipase;	A 22% B 50%
With triethylamine In tetrahydrofuran for 5h; Ambient temperature; pancreatin;	A 45% B 48%
With triethylamine In tetrahydrofuran for 5h; Ambient temperature; pancreatin;	A 45% B 48%
With triethylamine In tetrahydrofuran for 5h; Mechanism; Ambient temperature; pancreatin; other 2,2,2-trichloroethyl alkanoates;	A 45% B 48%

2,2,2-trichloroethyl acetate (625-24-1) + cis-3-acetoxy-5-hydroxycyclopent-1-ene (61740-26-9) → cis-1,4-diacetoxy-2-cyclopentene (54664-61-8) + (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

Conditions	Yield
With triethylamine In tetrahydrofuran for 5h; Ambient temperature; pancreatin;	A 49% B 46%

vinyl acetate (108-05-4) + cis-2-cyclopentenyl-1,4-diol (4157-01-1) → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

Conditions	Yield
With Pancreatin; triethylamine In tetrahydrofuran at 20℃; Enzymatic reaction;	14%

2,2,2-trichloroethyl acetate (625-24-1) + cis-4-cyclopentene-1,3-diol (29783-26-4) → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + (1R,4S)-4-hydroxy-2-cyclopentene-1-yl acetate (60410-16-4)

Conditions	Yield
pancreatin/base;

(1S,4R)-(-)-4-(2'R*-tetrahydropyranyloxy)-2-cyclopentenyl acetate (95722-35-3) → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + (1R,4S)-4-hydroxy-2-cyclopentene-1-yl acetate (60410-16-4)

Conditions	Yield
With toluene-4-sulfonic acid In ethanol for 2h; Ambient temperature; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

cyclopenta-1,3-diene (542-92-7) + Co2(CO)8 → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

Conditions	Yield
Multi-step reaction with 2 steps 1: 65 percent / O2; thiourea; Bengal rose / methanol / 18 h / -35 - 20 °C / Irradiation 2: 72 percent / Et3N; pancreatin / tetrahydrofuran / 3 h / 20 °C View Scheme

(2-furyl)methyl alcohol (98-00-0) → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

Conditions	Yield
Multi-step reaction with 5 steps 1: 53 percent / KH2PO4, H3PO4 / H2O / 40 h / 99 °C / pH 4.1 2: 76 percent / PPTs / tetrahydrofuran / 18 h / Ambient temperature 3: LiAlH4, LiI / various solvent(s); toluene / 0.5 h / -20 - -13 °C 4: 45 percent / Et3N, pancreatin, vinyl acetate / various solvent(s) / 7 h / Ambient temperature 5: p-TsOH / ethanol / 2 h / Ambient temperature View Scheme
Multi-step reaction with 5 steps 1: 53 percent / KH2PO4, H3PO4 / H2O / 40 h / 99 °C / pH 4.1 2: 72 percent / Et3N, DMAP / tetrahydrofuran / Ambient temperature 3: LiAlH4, LiI, TBSOH / toluene; various solvent(s) / 23 h / -30 - -25 °C 4: 48 percent / Et3N, pancreatin / various solvent(s) / 7 h / Ambient temperature 5: 67 percent / Et3N, TBAF / tetrahydrofuran / 2 h / Ambient temperature View Scheme
Multi-step reaction with 5 steps 1: 53 percent / KH2PO4, H3PO4 / H2O / 40 h / 99 °C / pH 4.1 2: 72 percent / Et3N, DMAP / tetrahydrofuran / Ambient temperature 3: LiAlH4, LiI, TBSOH / toluene; various solvent(s) / 23 h / -30 - -25 °C 4: 48 percent / Et3N, pancreatin, vinyl acetate / various solvent(s) / 7 h / Ambient temperature 5: 67 percent / Et3N, TBAF / tetrahydrofuran / 2 h / Ambient temperature View Scheme

4-Hydroxycyclopent-2-enone (59995-47-0, 59995-49-2, 61305-27-9, 61740-29-2) → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

Conditions	Yield
Multi-step reaction with 4 steps 1: 76 percent / PPTs / tetrahydrofuran / 18 h / Ambient temperature 2: LiAlH4, LiI / various solvent(s); toluene / 0.5 h / -20 - -13 °C 3: 45 percent / Et3N, pancreatin, vinyl acetate / various solvent(s) / 7 h / Ambient temperature 4: p-TsOH / ethanol / 2 h / Ambient temperature View Scheme
Multi-step reaction with 4 steps 1: 72 percent / Et3N, DMAP / tetrahydrofuran / Ambient temperature 2: LiAlH4, LiI, TBSOH / toluene; various solvent(s) / 23 h / -30 - -25 °C 3: 48 percent / Et3N, pancreatin / various solvent(s) / 7 h / Ambient temperature 4: 67 percent / Et3N, TBAF / tetrahydrofuran / 2 h / Ambient temperature View Scheme
Multi-step reaction with 4 steps 1: 72 percent / Et3N, DMAP / tetrahydrofuran / Ambient temperature 2: LiAlH4, LiI, TBSOH / toluene; various solvent(s) / 23 h / -30 - -25 °C 3: 48 percent / Et3N, pancreatin, vinyl acetate / various solvent(s) / 7 h / Ambient temperature 4: 67 percent / Et3N, TBAF / tetrahydrofuran / 2 h / Ambient temperature View Scheme

4-[(tert-butyldimethylsilyl)oxy]cyclopent-2-enone (61305-35-9, 61305-36-0, 61740-33-8, 56745-67-6) → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

Conditions	Yield
Multi-step reaction with 3 steps 1: LiAlH4, LiI, TBSOH / toluene; various solvent(s) / 23 h / -30 - -25 °C 2: 48 percent / Et3N, pancreatin / various solvent(s) / 7 h / Ambient temperature 3: 67 percent / Et3N, TBAF / tetrahydrofuran / 2 h / Ambient temperature View Scheme
Multi-step reaction with 3 steps 1: LiAlH4, LiI, TBSOH / toluene; various solvent(s) / 23 h / -30 - -25 °C 2: 48 percent / Et3N, pancreatin, vinyl acetate / various solvent(s) / 7 h / Ambient temperature 3: 67 percent / Et3N, TBAF / tetrahydrofuran / 2 h / Ambient temperature View Scheme
Multi-step reaction with 3 steps 1: lithium aluminium tetrahydride; lithium iodide / toluene; tert-butyl methyl ether / 3 h / -30 °C / Inert atmosphere; Large scale 2: triethylamine; Pancreatin / tert-butyl methyl ether / 7 h / Inert atmosphere; Large scale; Enzymatic reaction 3: triethylamine; tetrabutyl ammonium fluoride / tetrahydrofuran / Inert atmosphere View Scheme

4-(tetrahydro-pyran-2-yloxy)-cyclopent-2-enone (61305-37-1, 62356-78-9, 70615-05-3) → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

Conditions	Yield
Multi-step reaction with 3 steps 1: LiAlH4, LiI / various solvent(s); toluene / 0.5 h / -20 - -13 °C 2: 45 percent / Et3N, pancreatin, vinyl acetate / various solvent(s) / 7 h / Ambient temperature 3: p-TsOH / ethanol / 2 h / Ambient temperature View Scheme

(+/-)-cis-4-(2'R*-tetrahydropyranyloxy)-2-cyclopentenol (37517-41-2, 61375-54-0, 61375-55-1, 63640-56-2, 63640-57-3, 77341-50-5, 112458-81-8, 130792-62-0, 130792-63-1) → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

Conditions	Yield
Multi-step reaction with 2 steps 1: 45 percent / Et3N, pancreatin, vinyl acetate / various solvent(s) / 7 h / Ambient temperature 2: p-TsOH / ethanol / 2 h / Ambient temperature View Scheme

cis-(+/-)-4-<<(1,1-dimethylethyl)dimethylsilyl>oxy>-2-cyclopenten-1-ol (61305-33-7, 61692-07-7, 61692-08-8, 61740-30-5, 61740-31-6, 81939-24-4, 81939-25-5, 104069-09-2, 120520-91-4) → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

Conditions	Yield
Multi-step reaction with 2 steps 1: 48 percent / Et3N, pancreatin / various solvent(s) / 7 h / Ambient temperature 2: 67 percent / Et3N, TBAF / tetrahydrofuran / 2 h / Ambient temperature View Scheme
Multi-step reaction with 2 steps 1: 48 percent / Et3N, pancreatin, vinyl acetate / various solvent(s) / 7 h / Ambient temperature 2: 67 percent / Et3N, TBAF / tetrahydrofuran / 2 h / Ambient temperature View Scheme
Multi-step reaction with 2 steps 1: 48 percent / Et3N / various solvent(s) / pancreatin 2: 77 percent / tetrabutylammonium fluoride, Et3N / tetrahydrofuran View Scheme
Multi-step reaction with 2 steps 1: triethylamine; Pancreatin / tert-butyl methyl ether / 7 h / Inert atmosphere; Large scale; Enzymatic reaction 2: triethylamine; tetrabutyl ammonium fluoride / tetrahydrofuran / Inert atmosphere View Scheme

cis-4-cyclopentene-1,3-diol (29783-26-4) → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

cyclopenta-1,3-diene (542-92-7) → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

meso-cis-1,4-diacetoxy-2-cyclopentene (60389-71-1, 60410-14-2, 61826-75-3) → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

Conditions	Yield
With sodium hydroxide
Multi-step reaction with 2 steps 1: potassium hydrogencarbonate / methanol / Reflux 2: triethylamine; Pancreatin / tetrahydrofuran / 20 °C / Enzymatic reaction View Scheme

6-oxabicyclo[3.1.0]hex-2-ene (7129-41-1) + acetic acid (64-19-7) → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + (1R,4S)-4-hydroxy-2-cyclopentene-1-yl acetate (60410-16-4)

Conditions	Yield
With tetrakis(triphenylphosphine) palladium(0); Triethylene glycol dimethyl ether In tetrahydrofuran at 0℃; for 1h; Reagent/catalyst; Solvent; Schlenk technique; Inert atmosphere; Overall yield = 85 %Chromat.;	A n/a B n/a

3,5-cis-dibromocyclopentene (1890-04-6) → (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4)

Conditions	Yield
Multi-step reaction with 3 steps 1: N-benzyl-N,N,N-triethylammonium chloride / tert-butyl alcohol / Reflux 2: potassium hydrogencarbonate / methanol / Reflux 3: triethylamine; Pancreatin / tetrahydrofuran / 20 °C / Enzymatic reaction View Scheme

cis-1,4-diacetoxy-2-cyclopentene (54664-61-8) → cis-4-cyclopentene-1,3-diol (29783-26-4) + (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + (1R,4S)-4-hydroxy-2-cyclopentene-1-yl acetate (60410-16-4)

Conditions	Yield
With pseudomonas fluorescens lipase In hexane; water at 25℃; Reagent/catalyst; Enzymatic reaction; enantioselective reaction;
With lipase B from Candida antarctica In aq. phosphate buffer at 20℃; pH=7.5; Solvent; Enzymatic reaction;	A n/a B n/a C n/a

(1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + methanesulfonyl chloride (124-63-0) → (1S,4S)-1-acetoxy-4-methanesulfonyloxy-cyclopent-2-ene (177566-45-9)

Conditions	Yield
With triethylamine In dichloromethane 1.) 0 deg C to rt, 2.) rt, 6 h;	100%
With triethylamine In dichloromethane Ambient temperature;	100%

(1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + tert-butyldimethylsilyl chloride (18162-48-6) → (1R,3S)-(-)-1-acetoxycyclopentan-3-ol (103729-50-6)

Conditions	Yield
With dmap; triethylamine In dichloromethane at 23℃; for 12h;	99%
With 1H-imidazole In dichloromethane	90%
With 1H-imidazole In N,N-dimethyl-formamide

(1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + O-(4-methoxybenzyl)-trichloroacetimidate (89238-99-3) → (1S,4R)-1-acetyloxy-4-(4-methoxyphenylmethoxy)cyclopent-2-ene (1477979-57-9)

Conditions	Yield
With camphor-10-sulfonic acid In dichloromethane; pentane at 0 - 20℃; for 33h;	99%

(1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + [1-(4-bromo-phenyl)-hexyloxy]-tert-butyl-dimethyl-silane (836643-56-2) → 4-(4-(1-(t-butyldimethylsilyloxy)hexyl)phenyl)-2-cyclopenten-1-ol (836643-54-0)

Conditions	Yield
Stage #1: [1-(4-bromo-phenyl)-hexyloxy]-tert-butyl-dimethyl-silane With magnesium In tetrahydrofuran Stage #2: (1S,4R)-4-hydroxy-2-cyclopentenyl acetate With lithium chloride In tetrahydrofuran at 0℃; for 1h;	98%

(1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) → (1R,2R,4S,5S)-(-)-2-hydroxy-6-oxabicyclo<3.1.0>hex-4-yl acetate (137726-50-2)

Conditions	Yield
With 3-chloro-benzenecarboperoxoic acid In dichloromethane for 24h; Ambient temperature;	96%

(1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + tert-butylchlorodiphenylsilane (58479-61-1) → Acetic acid (1S,4R)-4-(tert-butyl-diphenyl-silanyloxy)-cyclopent-2-enyl ester (872624-44-7)

Conditions	Yield
With 1H-imidazole In N,N-dimethyl-formamide at 20℃;	95%

N-hydroxyphthalimide (524-38-9) + (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) → (1S,4S)-trans-1-acetoxy-4-(phthalimidooxy)-2-cyclopentene (163252-33-3)

Conditions	Yield
With triphenylphosphine; diethylazodicarboxylate In tetrahydrofuran Ambient temperature;	94%

(1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + benzyl bromide (100-39-0) → (1S,4R)-4-(benzyloxy)cyclopent-2-en-1-yl acetate (183612-92-2)

Conditions	Yield
With silver(l) oxide In dichloromethane at 20℃; for 12h;	93%
With silver(l) oxide In dichloromethane at 20℃; Inert atmosphere;	47.7%
With silver(l) oxide In dichloromethane at 20℃; for 168.5h; Inert atmosphere; Darkness;	47.7%

Benzyloxymethyl chloride (3587-60-8) + (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) → (1R,4R)-4-(benzyloxymethyl)cyclopent-2-enol (934986-74-0)

Conditions	Yield
Stage #1: Benzyloxymethyl chloride With bromine; magnesium; mercury dichloride In tetrahydrofuran at -5℃; for 2.5h; Stage #2: (1S,4R)-4-hydroxy-2-cyclopentenyl acetate In tetrahydrofuran at -20℃; for 0.25h; Further stages.;	92%

(1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + methyl 2-diazo-2-(dimethoxyphosphoryl)acetate (60190-78-5) → (+)-(1R,4S)-1-[(methoxycarbonyl)dimethyl phosphonomethoxy]-4-acetoxycyclopent-2-ene

Conditions	Yield
With dirhodium tetraacetate In benzene for 6h; Molecular sieve; Inert atmosphere; Reflux;	92%

(1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + 2',2',2'-trichloroethyl (E)-3-ethoxyacrylate (161029-10-3) → 2',2',2'-trichloroethyl (1''R,4''S)-3-(cis-4''-acetoxycyclopent-2''-enyloxy)-2-bromo-3-ethoxypropionate

Conditions	Yield
With N-Bromosuccinimide In dichloromethane Ambient temperature;	91%

(1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) → (1S,3R)-cis-3-acetoxycyclopentan-1-ol (149342-57-4)

Conditions	Yield
With sodium tetrahydroborate; hydrogen; nickel(II) acetate tetrahydrate In ethanol under 5171.62 Torr; for 4h; Autoclave;	87%
With hydrogen; nickel In ethanol at 15 - 20℃; under 750.06 - 3000.2 Torr; for 5h;	55%

C6H5ClMg*CCuN + (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) → (1R,4R)-4-phenylcyclopent-2-enol (913715-19-2)

Conditions	Yield
In tetrahydrofuran Grignard reaction;	87%

(1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + C15H23BrMgO2 → (1R,4R)-4-[7'-(4-methoxybenzyloxy)heptyl]-2-cyclopenten-1-ol (886841-24-3) + (1R,2R)-2-[7-(4-Methoxy-benzyloxy)-heptyl]-cyclopent-3-enol

Conditions	Yield
Stage #1: C15H23BrMgO2 With lithium chloride In tetrahydrofuran at -10℃; for 0.5h; Stage #2: (1S,4R)-4-hydroxy-2-cyclopentenyl acetate In tetrahydrofuran at -10℃; for 3h;	A 81% B n/a

(1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + phenyl isocyanate (103-71-9) → (1S,4R)-4-(((phenyl)carbamoyl)oxy)cyclopent-2-en-1-yl acetate

Conditions	Yield
With 1,8-diazabicyclo[5.4.0]undec-7-ene In dichloromethane at 23℃; Inert atmosphere;	81%

(1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + 4-Methoxyphenyl isocyanate (5416-93-3) → (1S,4R)-4-(((4-methoxyphenyl)carbamoyl)oxy)cyclopent-2-en-1-yl acetate

Conditions	Yield
With 1,8-diazabicyclo[5.4.0]undec-7-ene In dichloromethane at 23℃; Inert atmosphere;	81%

(1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + 2',2'-dichloroethyl (E)-3-ethoxyacrylate (161029-09-0) → 2',2'-dichloroethyl (1''R,4''S)-3-(cis-4''-acetoxycyclopent-2''-enyloxy)-2-bromo-3-ethoxypropionate

Conditions	Yield
With N-Bromosuccinimide In dichloromethane Ambient temperature;	77%

(1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + 2-[(E)-(S)-3-(tert-Butyl-dimethyl-silanyloxy)-oct-1-enyl]-4,5-dimethyl-[1,3,2]dioxaborolane (203301-80-8) → (1R,4R,1'E,3'S)-4-[{3'-(tert-butyldimethylsilyl)oxy}-1'-octenyl]-2-cyclopenten-1-ol (203301-59-1) + (1R,2S)-2-[(E)-(S)-3-(tert-Butyl-dimethyl-silanyloxy)-oct-1-enyl]-cyclopent-3-enol

Conditions	Yield
Stage #1: 2-[(E)-(S)-3-(tert-Butyl-dimethyl-silanyloxy)-oct-1-enyl]-4,5-dimethyl-[1,3,2]dioxaborolane With bis(triphenylphosphine)nickel(II) chloride; n-butyllithium; sodium iodide In tetrahydrofuran; hexane Cooling; Stage #2: (1S,4R)-4-hydroxy-2-cyclopentenyl acetate With tert-butyl isocyanide In tetrahydrofuran; hexane at 20℃; for 3h; Further stages.;	A 76% B 3.6%

(1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + 4-nitro-N-(prop-2-yn-1-yl)benzene-1-sulfonamide (221101-01-5) → Acetic acid (1S,4S)-4-[(4-nitro-benzenesulfonyl)-prop-2-ynyl-amino]-cyclopent-2-enyl ester

Conditions	Yield
With triphenylphosphine; diethylazodicarboxylate In tetrahydrofuran at 20℃; for 16h; Mitsunobu coupling;	76%

(1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + t-butyl diazoacetate (35059-50-8) → cis-(-)-{[(1R,4S)-4-acetoxycyclopent-2-en-1-yl]oxy}acetic acid tert-butyl ester (1073136-19-2)

Conditions	Yield
dirhodium tetraacetate In dichloromethane at 20℃; Inert atmosphere;	73.7%

ethyl 3-ethoxyacrylate (5941-55-9) + (1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) → ethyl (1'R,4'S)-3-(cis-4'-acetoxycyclopent-2'-enyloxy)-2-bromo-3-ethoxypropionate

Conditions	Yield
With N-Bromosuccinimide In dichloromethane Ambient temperature;	72%

(1S,4R)-4-hydroxy-2-cyclopentenyl acetate (60176-77-4) + methyl (E)-3-ethoxy-2-propenoate (78681-80-8) → methyl (1'R,4'S)-3-(cis-4'-acetoxycyclopent-2'-enyloxy)-2-bromo-3-ethoxypropionate

Conditions	Yield
With N-Bromosuccinimide In dichloromethane Ambient temperature;	67%

Upstream product

• 108-05-4 vinyl acetate 
• 29783-26-4 cis-4-cyclopentene-1,3-diol 
• 108-22-5 Isopropenyl acetate 
• 625-24-1 2,2,2-trichloroethyl acetate 
• 61740-26-9 cis-3-acetoxy-5-hydroxycyclopent-1-ene 
• 54664-61-8 cis-1,4-diacetoxy-2-cyclopentene 
• 103729-50-6 (1R,3S)-(-)-1-acetoxycyclopentan-3-ol 
• 7129-41-1 6-oxabicyclo[3.1.0]hex-2-ene 
• 64-19-7 acetic acid 
• 108-24-7 acetic anhydride 
• 95722-35-3 (1S,4R)-(-)-4-(2'R*-tetrahydropyranyloxy)-2-cyclopentenyl acetate 
• 542-92-7 cyclopenta-1,3-diene 
• 77-73-6 bi(cyclopentadiene) 
• 1890-04-6 3,5-cis-dibromocyclopentene 

Downstream Products

• 34638-25-0 (1R,5S)-2-oxabicyclo[3.3.0]oct-6-en-3-one 
• 26054-46-6 (-)-(1S,5R)-2-oxabicyclo[3.3.0]oct-6-en-3-one 
• 836643-54-0 4-(4-(1-(t-butyldimethylsilyloxy)hexyl)phenyl)-2-cyclopenten-1-ol 
• 884653-87-6 (1S,4R)-4-(6-{[bis-(4-methoxy-phenyl)-methyl]-amino}-2-chloro-purin-9-yl)-cyclopent-2-enol 
• 884654-09-5 (1S,4R)-4-[2-chloro-6-(2,2-diphenyl-ethylamino)-purin-9-yl]-cyclopent-2-enol 
• 934986-74-0 (1R,4R)-4-(benzyloxymethyl)cyclopent-2-enol 
• 886841-25-4 (R)-4-[7'-(4-methoxybenzyloxy)heptyl]-2-cyclopenten-1-one 
• 886841-27-6 (S)-4-[7-(4-Methoxy-benzyloxy)-heptyl]-5-[(E)-oct-2-en-(E)-ylidene]-cyclopent-2-enone 
• 154802-92-3 tert-butyl [(1S,4S)-4-hydroxycyclopent-2-en-1-yl]carbamate 
• 1290191-64-8 tert-butyl [(1R,3R)-3-hydroxycyclopentyl]carbamate 

Relevant articles and documents

IMMOBILIZED PORCINE LIVER ESTERASE: A CONVENIENT REAGENT FOR THE PREPARATION OF CHIRAL BUILDING BLOCKS

A simple method for the effective, covalent, immobilization of porcine liver esterase (PLE) is described, and the application of this reagent for the preparation of chiral building blocks on a 50-500 mmol scale is demonstrated.

Resolution of cis-4-O-TBS-2-cyclopenten-1,4-diol

The resolution of cis-4-O-TBS-2-cyclopenten-1,4-diol with a few different enzymes in organic medium is described. The optical purity and yield of both the alcohol and acetate were moderate to excellent.

Recombinant Pig Liver Esterase-Catalyzed Synthesis of (1S,4R)-4-Hydroxy-2-cyclopentenyl Acetate Combined with Subsequent Enantioselective Crystallization

The recombinant pig liver esterase catalyzed hydrolysis of cis-1,4-diacetoxy-2-cyclopentene forming (1S,4R)-4-hydroxy-2-cyclopentenyl acetate was investigated and realized at preparative scale. Relevant reaction conditions were examined and optimized to achieve full conversion with an enantiomeric excess of about 86% ee. Enantiopure product was then obtained after enantioselective crystallization, which required further studies of the solid phase behavior, including its binary melting point phase diagram.

Stereoselective Synthesis for Potential Isomers of Ticagrelor Key Starting Material

Tartrate salt of carbocyclic amine 2 is one of the key starting materials for the synthesis of Ticagrelor 1. During the synthesis of 1, the isomers of 2 also need to be considered as potential impurities and characterized before establishing the specification of product. In the present work, detailed study has been carried out to synthesize the related substances of 2, and their structure characterization has been discussed.

Cobalt versus Osmium: Control of Both trans and cis Selectivity in Construction of the EFG Rings of Pectenotoxin 4

Catalytic oxidative cyclisation reactions have been employed for the synthesis of the E and F rings of the complex natural product target pectenotoxin 4. The choice of metal catalyst (cobalt- or osmium-based) allowed for the formation of THF rings with either trans or cis stereoselectivity. Fragment union using a modified Julia reaction then enabled the synthesis of an advanced synthetic intermediate containing the EF and G rings of the target.