Nitrogen → (1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-9-(4-boronophenyl)-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]chrysene-3a-carboxylic acid

HRID 2405521Notes

Reaction equation

HRID 2405521 reaction equation
C([O:8][C:9]([C@:11]12[CH2:45][CH2:44][C@@H:43]([C:46]([CH3:48])=[CH2:47])[C@@H:12]1[C@@H:13]1[C@@:26]([CH3:29])([CH2:27][CH2:28]2)[C@@:25]2([CH3:30])[C@@H:16]([C@:17]3([CH3:42])[C@@H:22]([CH2:23][CH2:24]2)[C:21]([CH3:32])([CH3:31])[C:20]([C:33]2[CH:38]=[CH:37][C:36]([B:39]([OH:41])[OH:40])=[CH:35][CH:34]=2)=[CH:19][CH2:18]3)[CH2:15][CH2:14]1)=[O:10])C1C=CC=CC=1.N#N.B(Br)(Br)Br>C(Cl)Cl>[B:39]([C:36]1[CH:37]=[CH:38][C:33]([C:20]2[C:21]([CH3:32])([CH3:31])[C@H:22]3[C@:17]([CH3:42])([CH2:18][CH:19]=2)[C@@H:16]2[C@:25]([CH3:30])([C@@:26]4([CH3:29])[C@H:13]([CH2:14][CH2:15]2)[C@H:12]2[C@H:43]([C:46]([CH3:48])=[CH2:47])[CH2:44][CH2:45][C@:11]2([C:9]([OH:10])=[O:8])[CH2:28][CH2:27]4)[CH2:24][CH2:23]3)=[CH:34][CH:35]=1)([OH:41])[OH:40]

Participants

5

Reactant 3

HCID 947NitrogenHCID 25134Boron tribromideHCID 67775377(4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-((benzyloxy)carbonyl)-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)phenyl)boronic acid

Product 1

HCID 67775165(1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-9-(4-boronophenyl)-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]chrysene-3a-carboxylic acidYield 26.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
-78 °C

Procedure

A −78° C. solution of (4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-((benzyloxy)carbonyl)-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)phenyl)boronic acid (0.200 g, 0.308 mmol) in DCM (3 mL) was purged with N2(g). Boron tribromide (1M solution in DCM) (1.079 mL, 1.079 mmol) was added dropwise. The resulting yellow reaction mixture was stirred at −78° C. for 1 h. The cold bath was removed and H2O (5 mL) was added to quench the reaction. The resulting white paste was filtered and washed with H2O. The crude material was dissolved in THF and DCM loaded onto a silica gel column and eluted with 1:1 hexanes:EtOAc to give 93 mg crude material which was further purified by reverse phase HPLC to give (1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-9-(4-boronophenyl)-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]chrysene-3a-carboxylic acid (45.2 mg, 24.15%) as a white solid. 1H NMR (500 MHz, DMSO-d6) δ 12.09 (br. s., 1H), 7.97 (br. s., 2H), 7.68 (d, J=7.9 Hz, 2H), 7.04 (d, J=7.9 Hz, 2H), 5.18 (d, J=4.6 Hz, 1H), 4.70 (s, 1H), 4.57 (s, 1H), 3.02-2.90 (m, 1H), 2.33-2.23 (m, 1H), 2.12 (d, J=6.4 Hz, 1H), 2.05 (dd, J=17.2, 6.3 Hz, 1H), 1.80 (d, J=7.3 Hz, 2H), 1.69-1.66 (m, 1H), 1.65 (s, 3H), 1.56 (t, J=11.3 Hz, 1H), 1.50 (br. s., 1H), 1.45-1.36 (m, 8H), 1.33-1.28 (m, 1H), 1.23 (br. s., 1H), 1.21-1.12 (m, 3H), 1.02-0.98 (m, 1H), 0.97 (s, 3H), 0.93 (s, 6H), 0.87 (s, 3H), 0.86 (s, 3H).

Workup

  1. customThe cold bath was removed
  2. additionH2O (5 mL) was added
  3. customto quench
  4. customthe reaction
  5. filtrationThe resulting white paste was filtered
  6. washwashed with H2O
  7. dissolutionThe crude material was dissolved in THF
  8. washeluted with 1:1 hexanes
  9. customEtOAc to give 93 mg crude material which
  10. customwas further purified by reverse phase HPLC

Sources & evidence

ORD record
ord-a367894a561f41939cca96c0047d4b86
Source dataset
uspto-grants-2014_08
Patent number
US08802661B2

Reaction notes

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