Phosphorus oxide (P4O10) → HCID 69129823, compound

HRID 968148Notes

Reaction equation

HRID 968148 reaction equation
O=P12OP3(OP(OP(O3)(O1)=O)(=O)O2)=O.[Br:15][CH:16]([C:21](=[O:24])[CH2:22][Br:23])[CH2:17][C:18]([OH:20])=O>ClCCl>[Br:15][CH:16]1[C:21](=[CH:22][Br:23])[O:24][C:18](=[O:20])[CH2:17]1

Participants

4

Reactant 2

HCID 14812Phosphorus oxide (P4O10)HCID 230233pentanoic acid, 3,5-dibromo-4-oxo

Product 1

HCID 69129823HCID 69129823, compoundYield 83.1%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Phosphorus pentoxide (22.5 g) was added with stirring to a solution of 3,5-dibromo-4-oxopentanoic acid (30.4 g, 0.11 mol) in dry dichloromethane (500 ml). The mixture was heated at reflux with stirring for 2 h, and cooled to room temperature. The resulting mixture was filtered through a pad of filter aid, washed with brine, dried over sodium sulfate and evaporated to yield the tetrahydrofuranone (mixture of Z- and E-isomers in 4:1 ratio) as a pale yellow oil (23.4 g, 82%). The oil solidified on standing at room temperature overnight. Crystallisation from dichloromethane/light petroleum (60-80° C.) gave an analytically pure sample of the Z-isomer. m. p. 79° C. νmax 3094, 3027, 2947, 1799, 1634, 1393, 1289, 1114, 949, 838, 747, 718, 660 cm−1. λmax 279 nm (ε 4938). 1H n.m.r. δ (CDCl3) 3.10, dd, J 2.3 Hz, 18.8 Hz, Ha3; 3.45, dd, J 7.9 Hz, 18.8 Hz, Hb3; 5.07, m, H4; 5.90, s, 5-CHBr. 13C n.m.r. δ (CDCl3): 37.2, C3; 40.5, C4; 86.9, 5-CHBr, 152.3, C5; 169.5, C2.

Workup

  1. temperatureThe mixture was heated
  2. temperatureat reflux
  3. filtrationThe resulting mixture was filtered through a pad of filter aid
  4. washwashed with brine
  5. dry with materialdried over sodium sulfate
  6. customevaporated

Sources & evidence

ORD record
ord-49b255bafcb546bfa89aa6166d630c57
Source dataset
uspto-grants-2005_10
Patent number
US06958145B2

Reaction notes

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