Sodium Carbonate Monohydrate → methyl 6-((1R,3 aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-amino-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysen-9-yl)spiro[3.3]hept-5-ene-2-carboxylate

HRID 1400974Notes

Reaction equation

FC(F)(F)S(O[C:7]1[C:8]([CH3:36])([CH3:35])[C@H:9]2[C@:22]([CH3:25])([CH2:23][CH:24]=1)[C@@H:21]1[C@:12]([CH3:34])([C@@:13]3([CH3:33])[C@H:18]([CH2:19][CH2:20]1)[C@H:17]1[C@H:26]([C:29]([CH3:31])=[CH2:30])[CH2:27][CH2:28][C@:16]1([NH2:32])[CH2:15][CH2:14]3)[CH2:11][CH2:10]2)(=O)=O.CC1(C)C(C)(C)OB([C:47]2[CH2:57][C:49]3([CH2:52][CH:51]([C:53]([O:55][CH3:56])=[O:54])[CH2:50]3)[CH:48]=2)O1.O.C(=O)([O-])[O-].[Na+].[Na+]>O1CCOCC1.O.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[NH2:32][C@:16]12[CH2:28][CH2:27][C@@H:26]([C:29]([CH3:31])=[CH2:30])[C@@H:17]1[C@@H:18]1[C@@:13]([CH3:33])([CH2:14][CH2:15]2)[C@@:12]2([CH3:34])[C@@H:21]([C@:22]3([CH3:25])[C@@H:9]([CH2:10][CH2:11]2)[C:8]([CH3:35])([CH3:36])[C:7]([C:47]2[CH2:57][C:49]4([CH2:50][CH:51]([C:53]([O:55][CH3:56])=[O:54])[CH2:52]4)[CH:48]=2)=[CH:24][CH2:23]3)[CH2:20][CH2:19]1

Participants

Conditions

Temperature: 85 °C

Procedure

To a vial containing (1R,3aS,5aR,5bR,7aR,11aR,11bR,13aR,13bR)-3a-amino-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysen-9-yl trifluoromethanesulfonate (0.418 g, 0.749 mmol) was added methyl 6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)spiro[3.3]hept-5-ene-2-carboxylate (0.250 g, 0.899 mmol), sodium carbonate monohydrate (0.232 g, 1.874 mmol) and tetrakis(triphenylphosphine)palladium(0) (0.026 g, 0.022 mmol). The mixture was diluted with 1,4-dioxane (4 mL) and water (1 mL), then was flushed with nitrogen and the vial was sealed and heated to 85° C. After 5.5 h of heating, the mixture was cooled to rt, concentrated under reduced pressure, adsorbed to silica gel, and purified by chromatography using a 0-45% ethyl acetate in hexanes gradient and a 40 g Thomson silica gel column. The fractions containing the expected product were combined and concentrated under reduced pressure to give methyl 6-((1R,3 aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-amino-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysen-9-yl)spiro[3.3]hept-5-ene-2-carboxylate (0.31 g, 0.554 mmol, 73.9% yield) as an off-white solid. 1H NMR showed a mixture of the two diastereomers (0.8:1 ratio) which were not separated and were used in the next step with no additional purification. LCMS: m/e 560.47 (M+H)+, 2.46 min (method 2). Mixture of diastereomers: 1H NMR (500 MHz, chloroform-d) δ=6.00 (s, 0.45H, minor diastereomer), 5.84 (s, 0.55H, major diastereomer), 5.54 (td, J=6.1, 2.2 Hz, 1H), 4.75 (d, J=2.0 Hz, 1H), 4.62 (dd, J=2.3, 1.3 Hz, 1H), 3.71 (m, 3H), 3.13-2.99 (m, 1H), 2.70-2.31 (m, 7H), 2.18-1.84 (m, 4H), 1.72 (s, 3H), 1.18 (d, J=3.5 Hz, 3H), 1.10-1.08 (m, 6H), 0.99 (s, 3H), 0.85 (s, 3H), 1.68-0.83 (m, 19H).

Workup

customwas flushed with nitrogen
customthe vial was sealed
temperatureAfter 5.5 h of heating
temperaturethe mixture was cooled to rt
concentrationconcentrated under reduced pressure
custompurified by chromatography
additionThe fractions containing the expected product
concentrationconcentrated under reduced pressure

Sources & evidence

ORD record: ord-b94ea3e7da534b70954c05c34a04ea44
Source dataset: uspto-grants-2014_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08906889B2

Reaction notes

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