80736-41-0

Basic information

• Product Name: castasterone
• Synonyms: (22R,23R,24S)-2α,3α,22,23-Tetrahydroxy-24-methyl-5α-cholestan-6-one;(22R,23R,24S)-2α,3α,22,23-Tetrahydroxy-5α-ergostane-6-one;(2α,3α,5α,22R,23R,24S)-2,3,22,23-Tetrahydroxyergostan-6-one;BP 214
• CAS NO: 80736-41-0
• Molecular Formula: C₂₈H₄₈O₅
• Molecular Weight: 464.67772
• Product Categories: Bio-Pesticide;Intermediates & Fine Chemicals;Pharmaceuticals;Steroids
• Mol File: 80736-41-0.mol

Chemical Properties

• Melting Point: 259-260 °C
• Boiling Point: 598.7°C at 760 mmHg
• Flash Point: 329.9°C
• Appearance: /
• Density: 1.127g/cm³
• Vapor Pressure: 7.85E-17mmHg at 25°C
• Refractive Index: 1.541
• PKA: 14.29±0.20(Predicted)
• CAS DataBase Reference: castasterone(CAS DataBase Reference)
• NIST Chemistry Reference: castasterone(80736-41-0)
• EPA Substance Registry System: castasterone(80736-41-0)

Safety Data

• Hazardous Substances Data: 80736-41-0(Hazardous Substances Data)

Usage

Uses

Used in Agriculture:
Castasterone is used as a plant growth regulator for promoting plant growth and development. It enhances various aspects of plant growth, such as cell elongation, division, and differentiation, leading to improved crop yields and quality.
Used in Plant Biotechnology:
In the field of plant biotechnology, castasterone is used as a tool to study the molecular mechanisms underlying plant growth and development. It helps researchers understand the complex signaling pathways and gene regulation involved in plant growth, which can be utilized to develop improved crop varieties with enhanced growth characteristics.
Used in Plant Hormone Research:
Castasterone is also used in plant hormone research to explore its role in plant growth and development, as well as its interactions with other plant hormones. This research can provide valuable insights into the regulation of plant growth and help develop strategies for optimizing plant growth and productivity.

InChI:InChI=1/C28H48O5/c1-14(2)15(3)25(32)26(33)16(4)18-7-8-19-17-11-22(29)21-12-23(30)24(31)13-28(21,6)20(17)9-10-27(18,19)5/h14-21,23-26,30-33H,7-13H2,1-6H3/t15-,16-,17-,18+,19-,20-,21+,23-,24+,25+,26+,27+,28+/m0/s1

Synthetic route

(1R,3aS,3bS,5aS,6aS,9aR,10aR,10bS,12aS)-1-{(S)-1-[(4R,5R)-5-((S)-1,2-Dimethyl-propyl)-2,2-dimethyl-[1,3]dioxolan-4-yl]-ethyl}-8,8,10a,12a-tetramethyl-hexadecahydro-7,9-dioxa-dicyclopenta[a,h]phenanthren-5-one (111118-49-1) → castasterone (80736-41-0)

Conditions	Yield
With trifluoroacetic acid In methanol for 1h;	98%

(20S,22R,23R,24S)-23-(1-ethoxyethoxy)-6-ethylenedioxy-2α,3α-isopropylidenedioxy-5α-ergostan-22-ol (129824-69-7) → castasterone (80736-41-0)

Conditions	Yield
With hydrogenchloride In tetrahydrofuran for 3h; Heating;	94%
With hydrogenchloride In tetrahydrofuran	93.5%

2,3,22,23-tetra-O-acetylcastasterone (77027-48-6) → castasterone (80736-41-0)

Conditions	Yield
With potassium hydroxide for 1h; Heating;	94%

Δ2-(22R,23R,24S)-22,23-dihydroxy-24-methyl-5α-cholestan-6-one (130549-19-8) → castasterone (80736-41-0)

Conditions	Yield
With osmium(VIII) oxide; 4-methylmorpholine N-oxide In tetrahydrofuran; water; tert-butyl alcohol for 22h; Ambient temperature;	93%
With osmium(VIII) oxide; sulfuric acid; sodium sulfite 1.) pyridine, 15 min, 2.) pyridine, 30 min; Yield given. Multistep reaction;

(2R,3S,5α,22R,23R,24S)-6,6-Ethylenedioxy-2,3-isopropylidenedioxyergostane-22,23-diol (91708-76-8) → castasterone (80736-41-0)

Conditions	Yield
With acetic acid at 50℃; for 0.5h;	82%
With acetic acid In water at 50 - 60℃; for 1h;	7.62 g
With acid Yield given;

(22E,24S)-5α-ergost-2,22-dien-6-one (80779-45-9) → castasterone (80736-41-0)

Conditions	Yield
With (3a,9R,3'''a,4'"b,9'"R)-9,9'-[1,4-phthalazinediylbis(oxy)]bis[6'-(methyloxy)-10,11-dihydrocinchonan]; osmium(VIII) oxide; methanesulfonamide; potassium carbonate; potassium hexacyanoferrate(III) In water; tert-butyl alcohol for 15h; Ambient temperature;	80%

(22E)-24α-methyl-5α-cholesta-2,22-dien-6-one (72050-68-1, 80779-45-9, 95343-48-9, 116405-04-0, 147200-25-7) → C28H48O5 + castasterone (80736-41-0)

Conditions	Yield
With potassium osmate(VI) dihydrate; methanesulfonamide; potassium carbonate; potassium hexacyanoferrate(III); hydroquinidine (anthraquinone-1,4-diyl) diether In water; tert-butyl alcohol at 20℃; for 48h;	A n/a B 63%

trimethylaluminum (75-24-1) + (2R, 3S, 22R, 23S, 24R)-23,24-epoxy-6,6-ethylenedioxy-22-hydroxy-2,3-isopropylidenedioxy-5α-cholestane (86413-56-1) → castasterone (80736-41-0)

Conditions	Yield
With n-butyllithium; acetic acid 1) n-hexane, 69 h, room temperature; 2) 50 deg C, 30 min; Yield given. Multistep reaction;

(2R,3S,5S,8S,9S,10R,13S,14S,17R)-17-{(S)-1-[(4R,5R)-5-((S)-1,2-Dimethyl-propyl)-2,2-dimethyl-[1,3]dioxolan-4-yl]-ethyl}-2,3-dihydroxy-10,13-dimethyl-hexadecahydro-cyclopenta[a]phenanthren-6-one (83066-72-2) → castasterone (80736-41-0)

Conditions	Yield
With acetic acid In water at 65℃; for 4h; Yield given;

(22R,23R,24S)-22,23-diacetoxy-2α,3α-isopropylidenedioxy-5α-ergostan-6-one (106560-75-2) → castasterone (80736-41-0)

Conditions	Yield
With sodium hydroxide In methanol for 3h; Heating;	458 mg

(22E,24S)-3α,5-cyclo-5α-ergost-22-en-6-one (80779-43-7) → castasterone (80736-41-0)

Conditions	Yield
Multi-step reaction with 2 steps 1: 82 percent / pyridinium tolunen-p-sulfonate, LiBr / N,N-dimethyl-acetamide / 5 h / 160 °C 2: 80 percent / OsO4, K3, 1,4-bis(0-O-dihydroquinidinyl)phthalazine, K2CO3, methanesulfonamide / 2-methyl-propan-2-ol; H2O / 15 h / Ambient temperature View Scheme

(20S)-6-(1,3-dioxolan-2-yl)-3α,5-cyclo-20-formyl-5α-pregnane → castasterone (80736-41-0)

Conditions

Yield

Multi-step reaction with 8 steps 1: 57 percent / tetrahydrofuran / 1 h / Ambient temperature 2: 98 percent / propionic acid / xylene / 2 h / Heating 3: LiAlH4 / tetrahydrofuran / 2 h / Heating 4: Et3N / toluene / 2 h / 0 °C 5: LiAlH4 / tetrahydrofuran / Ambient temperature 6: 99 percent / 1 M H2SO4 / acetone / 2 h / Ambient temperature 7: 82 percent / pyridinium tolunen-p-sulfonate, LiBr / N,N-dimethyl-acetamide / 5 h / 160 °C 8: 80 percent / OsO4, K3, 1,4-bis(0-O-dihydroquinidinyl)phthalazine, K2CO3, methanesulfonamide / 2-methyl-propan-2-ol; H2O / 15 h / Ambient temperature View Scheme

(22S,23Z)-6-(1,3-dioxolan-2-yl)-3α,5-cyclo-26,27-bisnor-5α-cholest-23-en-22-ol (199169-93-2) → castasterone (80736-41-0)

Conditions

Yield

Multi-step reaction with 7 steps 1: 98 percent / propionic acid / xylene / 2 h / Heating 2: LiAlH4 / tetrahydrofuran / 2 h / Heating 3: Et3N / toluene / 2 h / 0 °C 4: LiAlH4 / tetrahydrofuran / Ambient temperature 5: 99 percent / 1 M H2SO4 / acetone / 2 h / Ambient temperature 6: 82 percent / pyridinium tolunen-p-sulfonate, LiBr / N,N-dimethyl-acetamide / 5 h / 160 °C 7: 80 percent / OsO4, K3, 1,4-bis(0-O-dihydroquinidinyl)phthalazine, K2CO3, methanesulfonamide / 2-methyl-propan-2-ol; H2O / 15 h / Ambient temperature View Scheme

(24S)-6-(1,3-dioxolane-2-yl)-24-methyl-3α,5-cyclo-5α-cholest-22-ene (199169-95-4) → castasterone (80736-41-0)

Conditions	Yield
Multi-step reaction with 3 steps 1: 99 percent / 1 M H2SO4 / acetone / 2 h / Ambient temperature 2: 82 percent / pyridinium tolunen-p-sulfonate, LiBr / N,N-dimethyl-acetamide / 5 h / 160 °C 3: 80 percent / OsO4, K3, 1,4-bis(0-O-dihydroquinidinyl)phthalazine, K2CO3, methanesulfonamide / 2-methyl-propan-2-ol; H2O / 15 h / Ambient temperature View Scheme

C30H48O3 → castasterone (80736-41-0)

Conditions

Yield

Multi-step reaction with 5 steps 1: Et3N / toluene / 2 h / 0 °C 2: LiAlH4 / tetrahydrofuran / Ambient temperature 3: 99 percent / 1 M H2SO4 / acetone / 2 h / Ambient temperature 4: 82 percent / pyridinium tolunen-p-sulfonate, LiBr / N,N-dimethyl-acetamide / 5 h / 160 °C 5: 80 percent / OsO4, K3, 1,4-bis(0-O-dihydroquinidinyl)phthalazine, K2CO3, methanesulfonamide / 2-methyl-propan-2-ol; H2O / 15 h / Ambient temperature View Scheme

(22E,24R)-6-(1,3-dioxolan-2-yl)-24-methyl-3α,5-cyclo-5α-cholest-22-en-26-oic acid ethyl ester (199169-94-3) → castasterone (80736-41-0)

Conditions

Yield

Multi-step reaction with 6 steps 1: LiAlH4 / tetrahydrofuran / 2 h / Heating 2: Et3N / toluene / 2 h / 0 °C 3: LiAlH4 / tetrahydrofuran / Ambient temperature 4: 99 percent / 1 M H2SO4 / acetone / 2 h / Ambient temperature 5: 82 percent / pyridinium tolunen-p-sulfonate, LiBr / N,N-dimethyl-acetamide / 5 h / 160 °C 6: 80 percent / OsO4, K3, 1,4-bis(0-O-dihydroquinidinyl)phthalazine, K2CO3, methanesulfonamide / 2-methyl-propan-2-ol; H2O / 15 h / Ambient temperature View Scheme

(22E,24R)-6-(1,3-dioxolan-2-yl)-26-methanesulfonyloxy-24-methyl-3α,5-cyclo-5α-cholest-22-ene (199169-96-5) → castasterone (80736-41-0)

Conditions

Yield

Multi-step reaction with 4 steps 1: LiAlH4 / tetrahydrofuran / Ambient temperature 2: 99 percent / 1 M H2SO4 / acetone / 2 h / Ambient temperature 3: 82 percent / pyridinium tolunen-p-sulfonate, LiBr / N,N-dimethyl-acetamide / 5 h / 160 °C 4: 80 percent / OsO4, K3, 1,4-bis(0-O-dihydroquinidinyl)phthalazine, K2CO3, methanesulfonamide / 2-methyl-propan-2-ol; H2O / 15 h / Ambient temperature View Scheme

3-methyl-butan-2-one (563-80-4) + ethyl halide → castasterone (80736-41-0)

Conditions	Yield
Multi-step reaction with 10 steps 1: Br2 / methanol 2: acetone / 18 h / Heating 3: NaH / tetrahydrofuran / 0.5 h / 25 °C 4: 80 percent / LDA / tetrahydrofuran / 1.) -40 to -50 deg C, 30 min, 2.) -75 deg C, 14 h 5: 83 percent / H2, pyridine / 10percent Pd/C / ethanol; tetrahydrofuran / 14 h / 2585.7 Torr / Ambient temperature 6: 99 percent / LAH / tetrahydrofuran / 1.) r.t. 2 h, 2.) reflux, overnight 7: 96 percent / CSA / 24 h / Ambient temperature 8: 91 percent / CrO3, pyridine / CH2Cl2 / 48 h / Ambient temperature 9: 72 percent / <(C6H5)3P>3RhCl / benzene / 5 h / Heating 10: 98 percent / aq. TFA / methanol / 1 h View Scheme
Multi-step reaction with 10 steps 1: Br2 / methanol 2: acetone / 18 h / Heating 3: 1.) NaH, triethylphosphonoacetate, 2.) aq. KOH / 1.) THF, 25 deg C, 30 min, 2.) 25 deg C, 24 h 4: 80 percent / LDA / tetrahydrofuran / 1.) -40 to -50 deg C, 30 min, 2.) -75 deg C, 14 h 5: 83 percent / H2, pyridine / 10percent Pd/C / ethanol; tetrahydrofuran / 14 h / 2585.7 Torr / Ambient temperature 6: 99 percent / LAH / tetrahydrofuran / 1.) r.t. 2 h, 2.) reflux, overnight 7: 96 percent / CSA / 24 h / Ambient temperature 8: 91 percent / CrO3, pyridine / CH2Cl2 / 48 h / Ambient temperature 9: 72 percent / <(C6H5)3P>3RhCl / benzene / 5 h / Heating 10: 98 percent / aq. TFA / methanol / 1 h View Scheme

4-(1-methylethyl)furan-2(5H)-one (10547-89-4) → castasterone (80736-41-0)

Conditions

Yield

Multi-step reaction with 7 steps 1: 80 percent / LDA / tetrahydrofuran / 1.) -40 to -50 deg C, 30 min, 2.) -75 deg C, 14 h 2: 83 percent / H2, pyridine / 10percent Pd/C / ethanol; tetrahydrofuran / 14 h / 2585.7 Torr / Ambient temperature 3: 99 percent / LAH / tetrahydrofuran / 1.) r.t. 2 h, 2.) reflux, overnight 4: 96 percent / CSA / 24 h / Ambient temperature 5: 91 percent / CrO3, pyridine / CH2Cl2 / 48 h / Ambient temperature 6: 72 percent / <(C6H5)3P>3RhCl / benzene / 5 h / Heating 7: 98 percent / aq. TFA / methanol / 1 h View Scheme

1-(acetyloxy)-3-methyl-2-butanone (36960-07-3) → castasterone (80736-41-0)

Conditions	Yield
Multi-step reaction with 8 steps 1: NaH / tetrahydrofuran / 0.5 h / 25 °C 2: 80 percent / LDA / tetrahydrofuran / 1.) -40 to -50 deg C, 30 min, 2.) -75 deg C, 14 h 3: 83 percent / H2, pyridine / 10percent Pd/C / ethanol; tetrahydrofuran / 14 h / 2585.7 Torr / Ambient temperature 4: 99 percent / LAH / tetrahydrofuran / 1.) r.t. 2 h, 2.) reflux, overnight 5: 96 percent / CSA / 24 h / Ambient temperature 6: 91 percent / CrO3, pyridine / CH2Cl2 / 48 h / Ambient temperature 7: 72 percent / <(C6H5)3P>3RhCl / benzene / 5 h / Heating 8: 98 percent / aq. TFA / methanol / 1 h View Scheme
Multi-step reaction with 8 steps 1: 1.) NaH, triethylphosphonoacetate, 2.) aq. KOH / 1.) THF, 25 deg C, 30 min, 2.) 25 deg C, 24 h 2: 80 percent / LDA / tetrahydrofuran / 1.) -40 to -50 deg C, 30 min, 2.) -75 deg C, 14 h 3: 83 percent / H2, pyridine / 10percent Pd/C / ethanol; tetrahydrofuran / 14 h / 2585.7 Torr / Ambient temperature 4: 99 percent / LAH / tetrahydrofuran / 1.) r.t. 2 h, 2.) reflux, overnight 5: 96 percent / CSA / 24 h / Ambient temperature 6: 91 percent / CrO3, pyridine / CH2Cl2 / 48 h / Ambient temperature 7: 72 percent / <(C6H5)3P>3RhCl / benzene / 5 h / Heating 8: 98 percent / aq. TFA / methanol / 1 h View Scheme

(22E)-stigmasta-2,22-dien-6-one (74174-45-1) → castasterone (80736-41-0)

Conditions

Yield

Multi-step reaction with 11 steps 1: 72 percent / OsO4, NMO, H2O / acetone; 2-methyl-propan-2-ol / 12 h / Ambient temperature 2: 98 percent / CSA / acetonitrile; CH2Cl2 / 1 h / Ambient temperature 3: OsO4, NMO, aq. NaHCO3, MeSO2NH2 / tetrahydrofuran; 2-methyl-propan-2-ol / 144 h / 40 °C 4: 82 percent / pyridine, NaHCO3, H5IO6 / tetrahydrofuran / 24 h / Ambient temperature 5: 80 percent / LDA / tetrahydrofuran / 1.) -40 to -50 deg C, 30 min, 2.) -75 deg C, 14 h 6: 83 percent / H2, pyridine / 10percent Pd/C / ethanol; tetrahydrofuran / 14 h / 2585.7 Torr / Ambient temperature 7: 99 percent / LAH / tetrahydrofuran / 1.) r.t. 2 h, 2.) reflux, overnight 8: 96 percent / CSA / 24 h / Ambient temperature 9: 91 percent / CrO3, pyridine / CH2Cl2 / 48 h / Ambient temperature 10: 72 percent / <(C6H5)3P>3RhCl / benzene / 5 h / Heating 11: 98 percent / aq. TFA / methanol / 1 h View Scheme

(22E,24S)-3β,5-cyclo-24-ethylcholest-22-en-6-one (74174-49-5) → castasterone (80736-41-0)

Conditions

Yield

Multi-step reaction with 12 steps 1: 80 percent / pyridine hydrochloride, LiBr / N,N-dimethyl-acetamide / 4 h / 160 °C 2: 72 percent / OsO4, NMO, H2O / acetone; 2-methyl-propan-2-ol / 12 h / Ambient temperature 3: 98 percent / CSA / acetonitrile; CH2Cl2 / 1 h / Ambient temperature 4: OsO4, NMO, aq. NaHCO3, MeSO2NH2 / tetrahydrofuran; 2-methyl-propan-2-ol / 144 h / 40 °C 5: 82 percent / pyridine, NaHCO3, H5IO6 / tetrahydrofuran / 24 h / Ambient temperature 6: 80 percent / LDA / tetrahydrofuran / 1.) -40 to -50 deg C, 30 min, 2.) -75 deg C, 14 h 7: 83 percent / H2, pyridine / 10percent Pd/C / ethanol; tetrahydrofuran / 14 h / 2585.7 Torr / Ambient temperature 8: 99 percent / LAH / tetrahydrofuran / 1.) r.t. 2 h, 2.) reflux, overnight 9: 96 percent / CSA / 24 h / Ambient temperature 10: 91 percent / CrO3, pyridine / CH2Cl2 / 48 h / Ambient temperature 11: 72 percent / <(C6H5)3P>3RhCl / benzene / 5 h / Heating 12: 98 percent / aq. TFA / methanol / 1 h View Scheme

(22E,24S)-2α,3α-dihydroxy-5α-stigmast-22-en-6-one (81481-12-1) → castasterone (80736-41-0)

Conditions

Yield

Multi-step reaction with 10 steps 1: 98 percent / CSA / acetonitrile; CH2Cl2 / 1 h / Ambient temperature 2: OsO4, NMO, aq. NaHCO3, MeSO2NH2 / tetrahydrofuran; 2-methyl-propan-2-ol / 144 h / 40 °C 3: 82 percent / pyridine, NaHCO3, H5IO6 / tetrahydrofuran / 24 h / Ambient temperature 4: 80 percent / LDA / tetrahydrofuran / 1.) -40 to -50 deg C, 30 min, 2.) -75 deg C, 14 h 5: 83 percent / H2, pyridine / 10percent Pd/C / ethanol; tetrahydrofuran / 14 h / 2585.7 Torr / Ambient temperature 6: 99 percent / LAH / tetrahydrofuran / 1.) r.t. 2 h, 2.) reflux, overnight 7: 96 percent / CSA / 24 h / Ambient temperature 8: 91 percent / CrO3, pyridine / CH2Cl2 / 48 h / Ambient temperature 9: 72 percent / <(C6H5)3P>3RhCl / benzene / 5 h / Heating 10: 98 percent / aq. TFA / methanol / 1 h View Scheme

(22E,24S)-2α,3α-Dihydroxy-5α-stigmast-22-en-6-one 2,3-acetonide (81481-13-2) → castasterone (80736-41-0)

Conditions	Yield
Multi-step reaction with 9 steps 1: OsO4, NMO, aq. NaHCO3, MeSO2NH2 / tetrahydrofuran; 2-methyl-propan-2-ol / 144 h / 40 °C 2: 82 percent / pyridine, NaHCO3, H5IO6 / tetrahydrofuran / 24 h / Ambient temperature 3: 80 percent / LDA / tetrahydrofuran / 1.) -40 to -50 deg C, 30 min, 2.) -75 deg C, 14 h 4: 83 percent / H2, pyridine / 10percent Pd/C / ethanol; tetrahydrofuran / 14 h / 2585.7 Torr / Ambient temperature 5: 99 percent / LAH / tetrahydrofuran / 1.) r.t. 2 h, 2.) reflux, overnight 6: 96 percent / CSA / 24 h / Ambient temperature 7: 91 percent / CrO3, pyridine / CH2Cl2 / 48 h / Ambient temperature 8: 72 percent / <(C6H5)3P>3RhCl / benzene / 5 h / Heating 9: 98 percent / aq. TFA / methanol / 1 h View Scheme
Multi-step reaction with 8 steps 1: 83.0 g / p-TsOH / 3 h / Heating 2: 30 g / ozone, NaHCO3 / methanol; CH2Cl2 / 2 h / -60 - -50 °C 3: n-BuLi / tetrahydrofuran; hexane / -50 to -60 deg C; -40 deg C, 1 h; -68 to - 65 deg C, 1 h; 0 deg C 4: 74.6 percent / 1.) triphenylphosphine, benzoic acid, diethyl azodicarboxylate; 2.) K2CO3 / 1.) THF, 5-10 deg C, 30 min; 2.) THF/methanol, reflux, 3 h 5: 44.3 g / H2, 1M NaBH4, ethylenediamine, nickel acetate / aq. ethanol / 5 h 6: 93 percent / m-chloroperbenzoic acid, Na2HPO4 / CH2Cl2 / 20 h / 5 °C 7: n-BuLi / hexane; cyclohexane / -70 deg C, 1 h; 10 deg C, 4 h 8: 7.62 g / 80percent AcOH / H2O / 1 h / 50 - 60 °C View Scheme
Multi-step reaction with 7 steps 1: 83.0 g / p-TsOH / 3 h / Heating 2: 30 g / ozone, NaHCO3 / methanol; CH2Cl2 / 2 h / -60 - -50 °C 3: 26.93 g / n-BuLi / tetrahydrofuran; hexane / -50 to -60 deg C; -40 deg C, 1 h; -68 to - 65 deg C, 1 h; 0 deg C 4: 44.3 g / H2, 1M NaBH4, ethylenediamine, nickel acetate / aq. ethanol / 5 h 5: 93 percent / m-chloroperbenzoic acid, Na2HPO4 / CH2Cl2 / 20 h / 5 °C 6: n-BuLi / hexane; cyclohexane / -70 deg C, 1 h; 10 deg C, 4 h 7: 7.62 g / 80percent AcOH / H2O / 1 h / 50 - 60 °C View Scheme

(22E,24S)-24-ethyl-3α,5-cyclo-5α-cholest-22-en-6-ol (103881-47-6) → castasterone (80736-41-0)

Conditions

Yield

Multi-step reaction with 13 steps 1: CrO3, H2SO4 / acetone 2: 80 percent / pyridine hydrochloride, LiBr / N,N-dimethyl-acetamide / 4 h / 160 °C 3: 72 percent / OsO4, NMO, H2O / acetone; 2-methyl-propan-2-ol / 12 h / Ambient temperature 4: 98 percent / CSA / acetonitrile; CH2Cl2 / 1 h / Ambient temperature 5: OsO4, NMO, aq. NaHCO3, MeSO2NH2 / tetrahydrofuran; 2-methyl-propan-2-ol / 144 h / 40 °C 6: 82 percent / pyridine, NaHCO3, H5IO6 / tetrahydrofuran / 24 h / Ambient temperature 7: 80 percent / LDA / tetrahydrofuran / 1.) -40 to -50 deg C, 30 min, 2.) -75 deg C, 14 h 8: 83 percent / H2, pyridine / 10percent Pd/C / ethanol; tetrahydrofuran / 14 h / 2585.7 Torr / Ambient temperature 9: 99 percent / LAH / tetrahydrofuran / 1.) r.t. 2 h, 2.) reflux, overnight 10: 96 percent / CSA / 24 h / Ambient temperature 11: 91 percent / CrO3, pyridine / CH2Cl2 / 48 h / Ambient temperature 12: 72 percent / <(C6H5)3P>3RhCl / benzene / 5 h / Heating 13: 98 percent / aq. TFA / methanol / 1 h View Scheme

1-bromo-3-methyl-2-butanone (19967-55-6) → castasterone (80736-41-0)

Conditions	Yield
Multi-step reaction with 9 steps 1: acetone / 18 h / Heating 2: NaH / tetrahydrofuran / 0.5 h / 25 °C 3: 80 percent / LDA / tetrahydrofuran / 1.) -40 to -50 deg C, 30 min, 2.) -75 deg C, 14 h 4: 83 percent / H2, pyridine / 10percent Pd/C / ethanol; tetrahydrofuran / 14 h / 2585.7 Torr / Ambient temperature 5: 99 percent / LAH / tetrahydrofuran / 1.) r.t. 2 h, 2.) reflux, overnight 6: 96 percent / CSA / 24 h / Ambient temperature 7: 91 percent / CrO3, pyridine / CH2Cl2 / 48 h / Ambient temperature 8: 72 percent / <(C6H5)3P>3RhCl / benzene / 5 h / Heating 9: 98 percent / aq. TFA / methanol / 1 h View Scheme
Multi-step reaction with 9 steps 1: acetone / 18 h / Heating 2: 1.) NaH, triethylphosphonoacetate, 2.) aq. KOH / 1.) THF, 25 deg C, 30 min, 2.) 25 deg C, 24 h 3: 80 percent / LDA / tetrahydrofuran / 1.) -40 to -50 deg C, 30 min, 2.) -75 deg C, 14 h 4: 83 percent / H2, pyridine / 10percent Pd/C / ethanol; tetrahydrofuran / 14 h / 2585.7 Torr / Ambient temperature 5: 99 percent / LAH / tetrahydrofuran / 1.) r.t. 2 h, 2.) reflux, overnight 6: 96 percent / CSA / 24 h / Ambient temperature 7: 91 percent / CrO3, pyridine / CH2Cl2 / 48 h / Ambient temperature 8: 72 percent / <(C6H5)3P>3RhCl / benzene / 5 h / Heating 9: 98 percent / aq. TFA / methanol / 1 h View Scheme

(20S)-2α,3α-isopropylidenedioxy-5α-pregnan-6-one-20-carbaldehyde (174656-33-8) → castasterone (80736-41-0)

Conditions

Yield

Multi-step reaction with 7 steps 1: 80 percent / LDA / tetrahydrofuran / 1.) -40 to -50 deg C, 30 min, 2.) -75 deg C, 14 h 2: 83 percent / H2, pyridine / 10percent Pd/C / ethanol; tetrahydrofuran / 14 h / 2585.7 Torr / Ambient temperature 3: 99 percent / LAH / tetrahydrofuran / 1.) r.t. 2 h, 2.) reflux, overnight 4: 96 percent / CSA / 24 h / Ambient temperature 5: 91 percent / CrO3, pyridine / CH2Cl2 / 48 h / Ambient temperature 6: 72 percent / <(C6H5)3P>3RhCl / benzene / 5 h / Heating 7: 98 percent / aq. TFA / methanol / 1 h View Scheme

(3S,4R,5R,6S)-6-((1R,3aS,3bS,5aS,6aS,9aR,10aR,10bS,12aS)-5-Hydroxy-8,8,10a,12a-tetramethyl-hexadecahydro-7,9-dioxa-dicyclopenta[a,h]phenanthren-1-yl)-3-isopropyl-heptane-1,4,5-triol → castasterone (80736-41-0)

Conditions	Yield
Multi-step reaction with 4 steps 1: 96 percent / CSA / 24 h / Ambient temperature 2: 91 percent / CrO3, pyridine / CH2Cl2 / 48 h / Ambient temperature 3: 72 percent / <(C6H5)3P>3RhCl / benzene / 5 h / Heating 4: 98 percent / aq. TFA / methanol / 1 h View Scheme

(1R,3aS,3bS,5aS,6aS,9aR,10aR,10bS,12aS)-1-((S)-1-{(4R,5R)-5-[(S)-1-(2-Hydroxy-ethyl)-2-methyl-propyl]-2,2-dimethyl-[1,3]dioxolan-4-yl}-ethyl)-8,8,10a,12a-tetramethyl-hexadecahydro-7,9-dioxa-dicyclopenta[a,h]phenanthren-5-ol → castasterone (80736-41-0)

Conditions	Yield
Multi-step reaction with 3 steps 1: 91 percent / CrO3, pyridine / CH2Cl2 / 48 h / Ambient temperature 2: 72 percent / <(C6H5)3P>3RhCl / benzene / 5 h / Heating 3: 98 percent / aq. TFA / methanol / 1 h View Scheme

(S)-3-{(4R,5R)-2,2-Dimethyl-5-[(S)-1-((1R,3aS,3bS,5aS,6aS,9aR,10aR,10bS,12aS)-8,8,10a,12a-tetramethyl-5-oxo-hexadecahydro-7,9-dioxa-dicyclopenta[a,h]phenanthren-1-yl)-ethyl]-[1,3]dioxolan-4-yl}-4-methyl-pentanal (174656-38-3) → castasterone (80736-41-0)

Conditions	Yield
Multi-step reaction with 2 steps 1: 72 percent / <(C6H5)3P>3RhCl / benzene / 5 h / Heating 2: 98 percent / aq. TFA / methanol / 1 h View Scheme

castasterone (80736-41-0) + acetic anhydride (108-24-7) → 2,3,22,23-tetra-O-acetylcastasterone (77027-48-6)

Conditions	Yield
With pyridine; dmap	100%
With dmap In pyridine for 15h; Ambient temperature;	98%
With dmap In pyridine at 20℃; for 15h;	98%

castasterone (80736-41-0) → 6α-hydroxycastasterone (220566-70-1) + 6β-hydroxycastasterone

Conditions	Yield
With sodium tetrahydroborate In methanol at 20℃; Reduction;	A 19% B 77%
With ethanol; sodium for 2h; Reduction; Heating;	A 53% B 10%

castasterone (80736-41-0) → (3α,5α,6α,8β,9α,12β,13β,16α,17β)-10-[(2'α,3'β,4'β,5'β)-3,4-dihydroxy-5,6-dimethyl-2-heptanyl]-5,6-dihydroxy-7a,9a-dimethylhexadecahydro-3H-benzo[c]indeno[5,4-e]oxepin-3-one (72962-43-7)

Conditions	Yield
Yield given. Multistep reaction;
Multi-step reaction with 2 steps 1: pyridine, N,N-dimethylaminopyridine View Scheme

castasterone (80736-41-0) → 6-deoxo-castasteron (87833-54-3)

Conditions	Yield
With potassium hydroxide; hydrazine hydrate In diethylene glycol for 2h; Heating;	1.7 mg

castasterone (80736-41-0) → 6α-hydroxycastasterone (220566-70-1)

Conditions	Yield
With ammonia In tetrahydrofuran; methanol at -78℃; for 2h;	39 mg

castasterone (80736-41-0) + 2,2-dimethoxy-propane (77-76-9) → (1R,3aS,3bS,5aS,6aS,9aR,10aR,10bS,12aS)-1-{(S)-1-[(4R,5S)-5-((S)-1,2-Dimethyl-propyl)-2,2-dimethyl-[1,3]dioxolan-4-yl]-ethyl}-8,8,10a,12a-tetramethyl-hexadecahydro-7,9-dioxa-dicyclopenta[a,h]phenanthren-5-one

Conditions	Yield
With toluene-4-sulfonic acid In dichloromethane Ambient temperature;

castasterone (80736-41-0) → Acetic acid (1R,3aS,3bS,6aS,8S,9R,10aR,10bS,12aS)-8-acetoxy-1-((1S,2R,3R,4S)-2,3-diacetoxy-1,4,5-trimethyl-hexyl)-10a,12a-dimethyl-5-oxo-6-trimethylsilanyl-octadecahydro-benzo[3,4]cyclohepta[1,2-e]inden-9-yl ester

Conditions	Yield
Multi-step reaction with 2 steps 1: 98 percent / 4-DMAP / pyridine / 15 h / 20 °C 2: BF3*Et2O / hexane; CH2Cl2 / 2.5 h / -20 - -15 °C View Scheme

castasterone (80736-41-0) → Acetic acid (1R,3aS,3bS,5S,6aS,8S,9R,10aR,10bS,12aS)-8-acetoxy-1-((1S,2R,3R,4S)-2,3-diacetoxy-1,4,5-trimethyl-hexyl)-10a,12a-dimethyl-6-oxo-5-trimethylsilanyl-octadecahydro-benzo[3,4]cyclohepta[1,2-e]inden-9-yl ester

Conditions	Yield
Multi-step reaction with 2 steps 1: 98 percent / 4-DMAP / pyridine / 15 h / 20 °C 2: BF3*Et2O / hexane; CH2Cl2 / 2.5 h / -20 - -15 °C View Scheme

castasterone (80736-41-0) → (1R,3aS,3bS,5R,5aS,6aS,9aR,10aR,10bS,12aS)-1-{(S)-1-[(4R,5S)-5-((S)-1,2-Dimethyl-propyl)-2,2-dimethyl-[1,3]dioxolan-4-yl]-ethyl}-8,8,10a,12a-tetramethyl-hexadecahydro-7,9-dioxa-dicyclopenta[a,h]phenanthren-5-ol

Conditions	Yield
Multi-step reaction with 2 steps 1: 77 percent / NaBH4 / methanol / 20 °C 2: 80 percent / p-toluenesulfonic acid / CH2Cl2 / 20 °C View Scheme

castasterone (80736-41-0) → (1R,3aS,3bS,5S,5aS,6aS,9aR,10aR,10bS,12aS)-1-{(S)-1-[(4R,5S)-5-((S)-1,2-Dimethyl-propyl)-2,2-dimethyl-[1,3]dioxolan-4-yl]-ethyl}-8,8,10a,12a-tetramethyl-hexadecahydro-7,9-dioxa-dicyclopenta[a,h]phenanthren-5-ol

Conditions	Yield
Multi-step reaction with 2 steps 1: 19 percent / NaBH4 / methanol / 20 °C 2: 68 percent / p-toluenesulfonic acid / CH2Cl2 / 20 °C View Scheme

castasterone (80736-41-0) → (2R,3S,5R,8S,9S,10R,13S,14S,17R)-17-((1S,2R,3R,4S)-2,3-Dihydroxy-1,4,5-trimethyl-hexyl)-10,13-dimethyl-6-methylene-hexadecahydro-cyclopenta[a]phenanthrene-2,3-diol

Conditions	Yield
Multi-step reaction with 3 steps 1: p-TsOH / CH2Cl2 / Ambient temperature 2: 79 percent / tetrahydrofuran / 2 h 3: 62 percent / aq. AcOH / tetrahydrofuran / 5 h / 70 °C View Scheme

castasterone (80736-41-0) → (1R,3aS,3bS,5aR,6aS,9aR,10aR,10bS,12aS)-1-{(S)-1-[(4R,5S)-5-((S)-1,2-Dimethyl-propyl)-2,2-dimethyl-[1,3]dioxolan-4-yl]-ethyl}-8,8,10a,12a-tetramethyl-5-methylene-hexadecahydro-7,9-dioxa-dicyclopenta[a,h]phenanthrene

Conditions	Yield
Multi-step reaction with 2 steps 1: p-TsOH / CH2Cl2 / Ambient temperature 2: 79 percent / tetrahydrofuran / 2 h View Scheme

Upstream product

• 74174-49-5 (22E,24S)-3β,5-cyclo-24-ethylcholest-22-en-6-one 
• 129824-67-5 (20S,22R,23R,24S,25S)-23-(1-ethoxyethoxy)-6-ethylenedioxy-2α,3α-isopropylidenedioxy-5α-ergostane-22,26-diol 
• 129824-63-1 (20S,22R,24Z)-6-ethylenedioxy-2α,3α-isopropylidenedioxy-23-oxo-5α-cholest-24-eno-26,22-lactone 
• 129824-64-2 (20S,22R,23R,24Z)-6-ethylenedioxy-23-hydroxy-2α,3α-isopropylidenedioxy-5α-cholest-24-eno-26,22-lactone 
• 129824-62-0 (20S,22R,24Z)-22,26-epoxy-6-ethylenedioxy-26-hydroxy-2α,3α-isopropylidenedioxy-5α-cholest-24-en-23-one 
• 140925-08-2 (20S,22R,23R,24S,25S)-23-(1-ethoxyethoxy)-6-ethylenedioxy-2α,3α-isopropylidenedioxy-5α-ergostano-26,22-lactone 
• 140925-07-1 (20S,22R,23R,24Z)-23-(1-ethoxyethoxy)-6-ethylenedioxy-2α,3α-isopropylidenedioxy-5α-cholest-24-eno-26,22-lactone 
• 129824-68-6 C₃₈H₆₆O₁₀S 
• 129824-60-8 (20S,22R,23Z,25Z)-23,26-epoxy-6-ethylenedioxy-22-hydroxy-2α,3α-isopropylidenedioxy-5α-cholesta-23,25-diene 
• 103382-92-9 3α,6α-diacetoxy-5β-pregnane-20-carbaldehyde 
• 121077-70-1 (22E)-3α,6α-diacetoxy-5β-cholesten-22-en-24-one 
• 57-87-4 Ergosterol 
• 3152-46-3 (22E,24R)-3α,5-cyclo-5α-ergost-22-en-6-one 
• 72050-68-1 (22E,24R)-5α-ergosta-2,22-dien-6-one 

Downstream Products

• 72962-43-7 (22R,23R,24R)-2α,3α,22,23-tetrahydro-B-homo-7-oxa-5α-ergostan-6-one 
• 72962-43-7 (22S,23S,24R)-2α,3α,22,23-tetrahydro-B-homo-7-oxa-5α-ergostan-6-one 
• 87833-54-3 6-deoxocastasterone 
• 72962-43-7 (3α,5α,6α,8β,9α,12β,13β,16α,17β)-10-[(2'α,3'β,4'β,5'β)-3,4-dihydroxy-5,6-dimethyl-2-heptanyl]-5,6-dihydroxy-7a,9a-dimethylhexadecahydro-3H-benzo[c]indeno[5,4-e]oxepin-3-one 

Relevant articles and documents

SYNTHESIS OF NATURALLY OCCURRING BRASSINOSTEROIDS EMPLOYING CLEAVAGE OF 23,24-EPOXIDES AS KEY REACTIONS. SYNTHESIS OF BRASSINOLIDE, CASTASTERONE, DOLICHOLIDE, DOLICHOSTERONE, HOMODOLICHOLIDE, HOMODOLICHOSTERONE, 6-DEOXOCASTASTERONE AND 6-DEOXODOLICHOSTERONE

Eight new plant growth-promoting steroids (brassinolide, castasterone, dolicholide, dolichosterone, homodolicholide, homodolichosterone, 6-deoxocastasterone and 6-deoxodolichosterone) were synthesized by the regio- and stereoselective ring-opening reactions of 23,24-epoxides prepared from stigmasterol.

New Synthesis of Castasterone

An improved synthesis that could produce gram quantities of castasterone was proposed. The starting material was stigmasterol, the cyclic part of which was transformed in the first synthetic step into the 3α,5-cyclo-6-ketone. The side-chain carbon skeleton in the target compound was constructed with the required stereochemistry of the C-24 methyl via addition of methylacetylene, hydrogenation of the propargyl alcohol over Lindlar catalyst, and Claisen rearrangement. Diols were introduced using Sharpless asymmetric dihydroxylation of the intermediate ?2,22-dienone in the presence of (DHQD)2AQN. A unique feature of the synthesis was the avoidance of chromatographic separations of propargyl alcohols with similar chromatographic mobilities because the C-22 diastereomers were enriched in subsequent redox reactions.

Improved Synthesis of Castasterone and Brassinolide

Castasterone 1 is synthesized in 32% overall yield in eight steps from the known (20S)-6,6-ethylenedioxy-20-formyl-3x,5-cyclo-5x-pregnane 4.

Improved synthesis of brassinolide

Brassinolide has been synthesized from stigmasterol in an overall yield of 7%. The key step in the synthesis is aldol condensation of 2α,3α-isopropylidenedioxy-6-oxo-23,24-dinor-5α-cholan-22-al with 3-isopropylbut-2-enolide carried out at -78°C, which gives a product with 22R,23R stereochemistry in high yield. Catalytic hydrogenation of this product is highly stereoselective leading to the desired 245 stereochemistry in an intermediate which is readily transformed into brassinolide. Copyright 1996 by the Royal Society of Chemistry.

Stereoselective Synthesis of Plant-Growth-Regulating Steroids: Brassinolide, Castasterone, and their 24,25-Substituted Analogues

Brassinosteroids and their congeners, brassinolide 1, castasterone 2, 25-methylbrassinolide 3, 25-methylcastasterone 4 and (24R)-24-phenylbrassinone 5, have been stereoselectively synthesized by employing the pyranone derivative 19 as a versatile intermediate for the construction of the side chain.

STEREOSELECTIVE SYNTHESIS OF THE BRASSINOLIDE SIDE CHAIN: NOVEL SYNTHESIS OF BRASSINOLIDE AND RELATED COMPOUNDS

A stereoselective synthesis of the brassinolide side chain involves the lactonization of Z-10 under acidic condition to give an α,β-unsaturated-δ-lactone 11 with the inversion of the configuration at C-22 of the epoxy steroid in quantitative yield.The 22R,23R,24R-γ-hydroxy-δ-lactone 14 was used as key intermediate for the syntheses of brassinolide (1), homobrassinolide (2), and typhasterol (4) as well as the side chain of the dolicholide (3).

A concise stereoselective synthesis of castasterone

A stereoselective synthesis of a brassinosteroid, castasterone, has been achieved by employing a pyranone derivative as a side-chain precursor.

SYNTHESIS OF BRASSINOLIDE AND ITS ANALOGS

A new version of the synthesis of brassinosteroids of the 28C series is described.It is based on stigmasterol and uses the reaction of steroidal 22-aldehydes with aryl sulfones.