7-Dehydrocholesterol → Previtamin D3

HRID 1077380Notes

Reaction equation

HRID 1077380 reaction equation
[CH3:1][C@@H:2]([C@@H:9]1[C@@:13]2([CH3:28])[CH2:14][CH2:15][C@@H:16]3[C@@:21]4([CH3:27])[CH2:22][CH2:23][C@H:24]([OH:26])[CH2:25][C:20]4=[CH:19][CH:18]=[C:17]3[C@@H:12]2[CH2:11][CH2:10]1)[CH2:3][CH2:4][CH2:5][CH:6]([CH3:8])[CH3:7]>CCCCCC>[CH3:27][C:21]1[CH2:22][CH2:23][C@H:24]([OH:26])[CH2:25][C:20]=1/[CH:19]=[CH:18]\[C:17]1[C@@H:12]2[CH2:11][CH2:10][C@H:9]([C@@H:2]([CH2:3][CH2:4][CH2:5][CH:6]([CH3:8])[CH3:7])[CH3:1])[C@@:13]2([CH3:28])[CH2:14][CH2:15][CH:16]=1

Participants

3

Reactant 1

HCID 4394237-Dehydrocholesterol

Product 1

HCID 5281058Previtamin D3

Reagents, catalysts & solvents 1

HCID 8058HexaneSolvent

Procedure

From the hexane data, it was concluded that the material eluted at 12.2 min is tachysterol. The size and kind of microreactor is important to the ratio of products formed. Where the microreactor is several times the size of the 7-DHC, the undesirable side reactions are more favored. For example the silica with 60 Å pores (Ex. 10 and 11) give a ratio of previtamin D3 :tachysterol similar to that of the reaction in hexane (Ex. 9). In micelles (Ex. 16), however, which form a similarly sized microreactor, but with an environment similar to that of a hydrocarbon solvent, tachysterol is very heavily favored.

Workup

  1. washeluted at 12.2 min
  2. customformed

Sources & evidence

ORD record
ord-f6bb1851d396499fbfe04619d81b2ea2
Source dataset
uspto-grants-1996_08
Patent number
US05543016

Reaction notes

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