Iodine → Spinosyn B

HRID 611799Notes

Reaction equation

HRID 611799 reaction equation
[CH3:1][CH2:2][C@@H:3]1[O:26][C:24](=[O:25])[CH2:23][C@@H:22]2[C:11](=[CH:12][C@@H:13]3[C@H:21]2[CH:20]=[CH:19][C@H:18]2[C@H:14]3[CH2:15][C@H:16]([O:27][C@@H:28]3[O:33][C@@H:32]([CH3:34])[C@H:31]([O:35][CH3:36])[C@@H:30]([O:37][CH3:38])[C@H:29]3[O:39][CH3:40])[CH2:17]2)[C:9](=[O:10])[C@H:8]([CH3:41])[C@@H:7]([O:42][C@@H:43]2[O:48][C@H:47]([CH3:49])[C@@H:46]([N:50](C)[CH3:51])[CH2:45][CH2:44]2)[CH2:6][CH2:5][CH2:4]1.O.O.O.C([O-])(=O)C.[Na+].II.[OH-].[Na+].[OH-].[NH4+]>CO.O.O>[C:24]([O-:26])(=[O:25])[CH3:23].[NH4+:50].[CH3:1][CH2:2][C@@H:3]1[O:26][C:24](=[O:25])[CH2:23][C@@H:22]2[C:11](=[CH:12][C@@H:13]3[C@H:21]2[CH:20]=[CH:19][C@H:18]2[C@H:14]3[CH2:15][C@H:16]([O:27][C@@H:28]3[O:33][C@@H:32]([CH3:34])[C@H:31]([O:35][CH3:36])[C@@H:30]([O:37][CH3:38])[C@H:29]3[O:39][CH3:40])[CH2:17]2)[C:9](=[O:10])[C@H:8]([CH3:41])[C@@H:7]([O:42][C@@H:43]2[O:48][C@H:47]([CH3:49])[C@@H:46]([NH:50][CH3:51])[CH2:45][CH2:44]2)[CH2:6][CH2:5][CH2:4]1

Participants

9

Reactant 5

HCID 807IodineHCID 14798Sodium HydroxideHCID 14923Ammonium HydroxideHCID 443059Spinosyn AHCID 23665404Sodium Acetate Trihydrate

Product 2

HCID 443060Spinosyn BYield 136.8%HCID 517165Ammonium AcetateYield 0.05%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 22242641Methanol--water (1/1)Solvent

Conditions

Temperature
47 °C

Procedure

A suspension of Spinosyn A (5.0 gms, 5.13 mmol) and sodium acetate trihydrate (4.68 gms, 34.4 mmol) in 80% methanol/water (125 ml) was heated to 47° C. under nitrogen. The pH dropped from 10 to 8 on addition of iodine (1.75 gms, 68.0 mmol) as a solid in one portion, giving a brown color. The pH was maintained at 8-9 by periodic addition of 1N sodium hydroxide. The reaction was heated for 2.75 h (during which time the color faded to pale yellow), and was then cooled to ambient temperature. The solution was poured into a solution of water (250 ml) and ammonium hydroxide (50 ml), and extracted with diethyl ether. The ether extract was washed with brine, dried (K2CO3), and evaporated at ambient temperature under vacuum. The crude product was purified by reversed phase HPLC on a C18 column, eluting with methanol:acetonitrile:0.05% ammonium acetate (45:45:10) giving Spinosyn B (2.52 gms) which was identical (MS, 1H NMR, 13C NMR, IR, and OR) to a naturally produced sample of Spinosyn B.

Workup

  1. customgiving a brown color
  2. temperatureThe reaction was heated for 2.75 h (during which time the color
  3. temperaturewas then cooled to ambient temperature
  4. extractionextracted with diethyl ether
  5. extractionThe ether extract
  6. washwas washed with brine
  7. dry with materialdried (K2CO3)
  8. customevaporated at ambient temperature under vacuum
  9. customThe crude product was purified by reversed phase HPLC on a C18 column
  10. washeluting with methanol

Sources & evidence

ORD record
ord-1d719139a6394154a6d3e6cf0a75ae91
Source dataset
uspto-grants-1999_12
Patent number
US06001981

Reaction notes

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