Trifluoroacetic acid → (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

HRID 1400969Notes

Reaction equation

HRID 1400969 reaction equation
[F:1][C:2]([F:45])([F:44])[S:3]([O:6][C:7]1[C:8]([CH3:43])([CH3:42])[C@H:9]2[C@:22]([CH3:25])([CH2:23][CH:24]=1)[C@@H:21]1[C@:12]([CH3:41])([C@@:13]3([CH3:40])[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([NH:32]C(OC(C)(C)C)=O)[CH2:15][CH2:14]3)[CH2:11][CH2:10]2)(=[O:5])=[O:4].FC(F)(F)C(O)=O>ClCCl>[F:44][C:2]([F:1])([F:45])[S:3]([O:6][C:7]1[C:8]([CH3:43])([CH3:42])[C@H:9]2[C@:22]([CH3:25])([CH2:23][CH:24]=1)[C@@H:21]1[C@:12]([CH3:41])([C@@:13]3([CH3:40])[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:4])=[O:5]

Participants

4

Reactant 2

HCID 6422Trifluoroacetic acidHCID 71698572(1R,3aS,5aR,5bR,7aR,11aR,11bR,13aR,13bR)-3a-((tert-butoxycarbonyl)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

Product 1

HCID 71698571(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 trifluoromethanesulfonateYield 64.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of (1R,3aS,5aR,5bR,7aR,11aR,11bR,13aR,13bR)-3a-((tert-butoxycarbonyl)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 (0.2 g, 0.304 mmol) in dichloromethane (2 mL) was added trifluoroacetic acid (0.5 mL, 6.49 mmol). The mixture was stirred at rt for 1.5 h then was concentrated under reduced pressure. The residue was diluted with saturated aqueous sodium bicarbonate (20 mL) and extracted with dichloromethane (3×20 mL). The combined organic layers were dried with sodium sulfate. The drying agent was removed by filtration. The filtrate was concentrated and adsorbed to silica gel and purified using a 12-100% ethyl acetate in hexanes gradient and a 12 g Thomson silica gel column. The fractions containing the expected product were combined and were concentrated under reduced pressure to give (1R,3aS,5aR,5bR,7aR,11aR,11bR,13 aR,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 (0.109 g, 0.195 mmol, 64.3% yield) as an off-white solid. 1H NMR (500 MHz, chloroform-d) δ=5.57 (dd, J=6.8, 1.9 Hz, 1H), 4.73 (d, J=1.6 Hz, 1H), 4.63-4.60 (m, 1H), 2.54 (td, J=10.9, 5.3 Hz, 1H), 2.17 (dd, J=17.1, 6.9 Hz, 1H), 2.08-1.99 (m, 1H), 1.70 (s, 3H), 1.13 (s, 3H), 1.08 (s, 3H), 1.03 (s, 3H), 0.97 (s, 3H), 0.93 (s, 3H), 1.82-0.91 (m, 20H).

Workup

  1. concentrationthen was concentrated under reduced pressure
  2. additionThe residue was diluted with saturated aqueous sodium bicarbonate (20 mL)
  3. extractionextracted with dichloromethane (3×20 mL)
  4. dry with materialThe combined organic layers were dried with sodium sulfate
  5. customThe drying agent was removed by filtration
  6. concentrationThe filtrate was concentrated
  7. custompurified
  8. additionThe fractions containing the expected product
  9. concentrationwere concentrated under reduced pressure

Sources & evidence

ORD record
ord-730d057d0a6b47c6b6718839c23c408f
Source dataset
uspto-grants-2014_12
Patent number
US08906889B2

Reaction notes

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