Tylosin B → 19-deformyldesmycosin

HRID 1088420Notes

Reaction equation

HRID 1088420 reaction equation
[CH3:1][CH2:2][C@H:3]1[O:20][C:18](=[O:19])[CH2:17][C@@H:16]([OH:21])[C@H:15]([CH3:22])[C@@H:14]([O:23][C@@H:24]2[O:29][C@H:28]([CH3:30])[C@@H:27]([OH:31])[C@H:26]([N:32]([CH3:34])[CH3:33])[C@H:25]2[OH:35])[C@@H:13]([CH2:36]C=O)[CH2:12][C@@H:11]([CH3:39])[C:9](=[O:10])[CH:8]=[CH:7][C:6]([CH3:40])=[CH:5][C@@H:4]1[CH2:41][O:42][C@@H:43]1[O:48][C@H:47]([CH3:49])[C@@H:46]([OH:50])[C@@H:45]([O:51][CH3:52])[C@H:44]1[O:53][CH3:54]>C1C=CC=CC=1.C(OCC)(=O)C>[CH3:1][CH2:2][CH:3]1[O:20][C:18](=[O:19])[CH2:17][CH:16]([OH:21])[CH:15]([CH3:22])[CH:14]([O:23][CH:24]2[O:29][CH:28]([CH3:30])[CH:27]([OH:31])[CH:26]([N:32]([CH3:33])[CH3:34])[CH:25]2[OH:35])[CH:13]([CH3:36])[CH2:12][CH:11]([CH3:39])[C:9](=[O:10])[CH:8]=[CH:7][C:6]([CH3:40])=[CH:5][CH:4]1[CH2:41][O:42][CH:43]1[O:48][CH:47]([CH3:49])[CH:46]([OH:50])[CH:45]([O:51][CH3:52])[CH:44]1[O:53][CH3:54]

Participants

4

Reactant 1

HCID 6437804Tylosin B

Product 1

HCID 644405819-deformyldesmycosinYield 73%

Reagents, catalysts & solvents 2

HCID 241BenzeneSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
90 °C

Procedure

Desmycosin (Merck Index, Tenth Edition p. 1405) (18.9 o) was dissolved in degassed benzene (580 mL) and tris(triphenYlphospbine)rhodium chloride (29.5 g.) was added. The mixture was heated under dry nitrogen at 90° C. for 16 h. The mixture was diluted with ethyl acetate and extracted twice with 0.2N hydrochloric acid. The aqueous acid layer was adjusted to pH 10 and extracted with dichloromethane. The latter was dried (MgSO4), filtered and evaporated to dryness. The residue was chromatographed on a silica gel column (60×5 cm.) using 5% methanol in chloroform (v/v) as the eluant to give 19deformyldesmycosin (13.2 g., 73%) as a colorless amorphous solid (Anal.: found: C, 57.05; H, 7.99; N, 1.62%. C38H65NO13. 0.5 CHCl3 requires C, 56.79; H, 8.15; N, 1.74%); MS: m/z 744 (MH+); Rotation: [α]D26 0° (CHCl3); UV: λmax (CH3OH) 282 nm (ε20,676); IR: νmax (CDCl3) 3540, 3450, 1705, 1670, 1590, 1185, 1163, 1055 cm-1 ; 1H-NMR: δH (CDCl3) 0.92 (3H,tJ16,17-CH3 7 Hz, 17-CH3), 1.02 (3H,d,J 7 Hz, CH3), 1.03 (3 H,d,J 7 Hz, CH3), 1.18 (3H,d,J 7 Hz, CH3), 1.26 (3H,d,J 7 Hz, CH3), 1.30 (3H,d,J 7 Hz, CH3), 1.78 (3H,d,J12 -CH3,13 1 Hz, 12-CH3), 2.53 (6H,s,3'-N(CH3)2), 3.48 (3H,s,2"-OCH3), 3.60 (3H,s,3"-OCH3), 4.28 (1H,d,J1'ax,2'ax 8 Hz, H1'ax), 4.55 (1H,d,J1"ax,2"ax 8 Hz, H1"ax), 4.97 (1H,m,H15), 5.82 (1H,dc,J12-CH3,13 1 Hz, J13,14 10 Hz, H13), 6.24 (1H,d,J10,11 16 Hz, H10), and 7.24 (1H,d,J10,11 16 Hz, H11)

Workup

  1. extractionextracted twice with 0.2N hydrochloric acid
  2. extractionextracted with dichloromethane
  3. dry with materialThe latter was dried (MgSO4)
  4. filtrationfiltered
  5. customevaporated to dryness
  6. customThe residue was chromatographed on a silica gel column (60×5 cm.)

Sources & evidence

ORD record
ord-27af18d1bf8a4de498dc281add7859b4
Source dataset
uspto-grants-1990_10
Patent number
US04962146

Reaction notes

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