Methyl 7-hydroxyhept-5-ynoate → Methyl cis-7-Hydroxy-5-heptenoate

HRID 2351798Notes

Reaction equation

HRID 2351798 reaction equation
[OH:1][CH2:2][C:3]#[C:4][CH2:5][CH2:6][CH2:7][C:8]([O:10][CH3:11])=[O:9]>[Pd].CC([O-])=O.CC([O-])=O.[Pb+2].CCCCCC.CCOC(C)=O>[OH:1][CH2:2]/[CH:3]=[CH:4]\[CH2:5][CH2:6][CH2:7][C:8]([O:10][CH3:11])=[O:9]

Participants

4

Reactant 1

HCID 11789443Methyl 7-hydroxyhept-5-ynoate

Product 1

HCID 15586879Methyl cis-7-Hydroxy-5-heptenoate

Reagents, catalysts & solvents 2

HCID 131709914Lindlars catalystCatalystHCID 21226206Ethyl acetate hexaneSolvent

Procedure

Lindlar catalyst (palladium on calcium carbonate, poisoned with lead; 60 mg) was added to a solution of alkyne 38 (1.26 g, 8.07 mmol) in 2:1 hexane/EtOAc at 0° C. Hydrogen was bubbled through the reaction mixture until TLC analysis indicated the disappearance of 38 (2-3 h). The mixture was filtered and concentrated to yield 39 was a colorless liquid (1.277 g, 100%): IR (neat) 3410 (br), 3015 (w), 2940 (s), 2860, 1740 (s), 1435,, 1365, 1245, 1205, 1155, 1025, 1000 cm-1 ; 1H NMR (CDCl3) δ 5.66 (ddt, J1 =10.9 Hz, J2 -6.8 Hz, J3 =1.4 Hz, 1H), 5.44 (dtt, J1 =10.9 Hz, J2 =7.5 Hz, J3 =1.3 Hz, 1H), 4.15 (dd, J1 =6.7 Hz, J2 =1.1 Hz, 2H), 3.66 (s, 3H), 2.32 (t, J=7.3 Hz, 2H), 2.12 (dq, J1 =7.5 Hz, J2 =1.1 Hz, 2H), 1.99 (br, 1H), 1.71 (p, J=7.3 Hz, 2H9. A minor amount (ca. 3%) of methyl trans-7-hydroxy-5-heptenoate could be seen in the 1H NMR spectrum at δ 4.09. The longer the reaction proceeded beyond completion, the greater the amount of this product was produced.

Workup

  1. customHydrogen was bubbled through the reaction mixture until TLC analysis
  2. customthe disappearance of 38 (2-3 h)
  3. filtrationThe mixture was filtered
  4. concentrationconcentrated

Sources & evidence

ORD record
ord-2402f57d43ef46e39ae2c19ec6e4bddf
Source dataset
uspto-grants-1989_10
Patent number
US04873360

Reaction notes

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