p-Toluenesulfonic acid → 1-Oxaspiro[4.5]dec-7-ene

HRID 1980404Notes

Reaction equation

HRID 1980404 reaction equation
[C:1]1([CH2:7][CH2:8][CH2:9][OH:10])[CH2:6][CH:5]=[CH:4][CH2:3][CH:2]=1.C1(C)C=CC(S(O)(=O)=O)=CC=1>O>[O:10]1[C:1]2([CH2:6][CH2:5][CH:4]=[CH:3][CH2:2]2)[CH2:7][CH2:8][CH2:9]1

Participants

4

Reactant 2

HCID 6101p-Toluenesulfonic acidHCID 20402847HCID 20402847, compound

Product 1

HCID 132984301-Oxaspiro[4.5]dec-7-eneYield 76%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
115 °C

Procedure

This crude 3-(1,4-cyclohexadienyl)propan-1-ol thus obtained was divided into two batches. Each batch was treated separately with 2.5 g of p-toluenesulfonic acid. The pressure was lowered to 12 mmHg and the pot immersed in an oil bath heated to 115° C. After about 0.3 hr distillation through a short vacuum jacketed vigreaux column at reduced pressure began and continued at a steady rate as cyclization proceeded. A total of 105.4 g (76% yield) of the 1-oxaspiro[4.5]dec-7-ene was obtained as a water white liquid, bp 79°-81° C. (12 mmHg). The NMR spectrum was identical to that for the same compound described in Example 1 above, step E.

Workup

  1. customthe pot immersed in an oil bath
  2. distillationAfter about 0.3 hr distillation through a short vacuum

Sources & evidence

ORD record
ord-9b678156e3c2476e828bbc5a0f869dfe
Source dataset
uspto-grants-1985_04
Patent number
US04508911

Reaction notes

Loading…