p-Toluenesulfonic acid → dihydrospiro[cyclohexane-1,2'(1'H)-naphthalene]-4',4-dione

HRID 1580259Notes

Reaction equation

HRID 1580259 reaction equation
[CH2:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[C:4](=[O:11])[CH2:3][C:2]21[CH2:16][CH2:15][C:14](=[O:17])[CH2:13][CH2:12]2.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1C=CC=CC=1>[CH2:1]1[C:10]2[CH:5]([CH2:6][CH:7]=[CH:8][CH:9]=2)[C:4](=[O:11])[CH2:3][C:2]21[CH2:16][CH2:15][C:14](=[O:17])[CH2:13][CH2:12]2

Participants

4

Reactant 2

HCID 6101p-Toluenesulfonic acidHCID 122512663', 4'-dihydrospiro[cyclohexane-1,2'(1'H)-naphthalene]-4', 4-dione

Product 1

HCID 68134593dihydrospiro[cyclohexane-1,2'(1'H)-naphthalene]-4',4-dione

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

A 3', 4'-dihydrospiro[cyclohexane-1,2'(1'H)-naphthalene]-4', 4-dione (6) obtained in step (6) is monoketalized at the non-conjugated least hindered carbonyl function, e.g., by heating (at reflux) in a solvent such as benzene with an alkylene glycol (in the presence of a catalyst such as p-toluenesulfonic acid), to yield a corresponding 3', 4', -dihydrospiro[cyclohexane-1,2'(1'H)-naphthalene]-4',4 -dione, 4-(ethylene ketal) (7).

Workup

  1. temperatureby heating

Sources & evidence

ORD record
ord-07cbd9b2d42443c9a221499eba3a271b
Source dataset
uspto-grants-1976_01
Patent number
US03932425

Reaction notes

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