§
Luxuse
Patent Intelligence
Sign In
Patent EP0039089A2 successfully refreshed from Google Patents.
← Back to Patent Explorer
EP0039089A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Process for preparing cyclopentenolones

Assignee: Sumitomo Chemical Co Ltd
•
Filing: 1981-04-30
•
Granted: —
•
Expires: 2001-04-30
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A process is described for preparing cyclopentenolones in good yields which comprises treating a 4-hydroxy-4-R 2 -5-R 1 -2-cyclopentenone of the formula: wherein R 1 is an alkyl group having not more than 6 carbon atoms, an alkenyl group having not more than 6 carbon atoms, an alkynyl group having not more than 6carbon atoms or a group of the formula: (in which R 3 is hydrogen, methyl or halogen) and R 2 is a hydrogen atom or a methyl group, provided that when R 2 is hydrogen, R 1 is neither a-methylallyl nor a-methylpropargyl, in an aqueous medium in the presence or absence of a metal salt at a temperature of 20 to 200°C to give the corresponding 2-R 1 -3-R 2 -4-hydroxy-2-cyclopentenone of the formula: wherein R 1 and R 2 are each as defined above.

Inventors

  • 👤 Kenji Saito
  • 👤 Hiroshi Yamachika
  • 👤 Masayoshi Minai

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-07 16:41
CPC Classifications
C; C07; C07C; C07C45/00; C07C45/61; C07C45/67

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 119 words
A process for preparing cyclopentenolones which comprises treating a 4-hydroxy-4-R 2 -5-R l -2-cyclo- pentenone of the formula: wherein R 1 is an alkyl group having not more than 6 carbon atoms, an alkenyl group having not more than 6 carbon atoms, an alkynyl group having not more than 6 carbon atoms or a group of the formula: (in which R 3 is hydrogen, methyl or halogen) and R 2 is a hydrogen atom or a methyl group, provided that when R 2 is hydrogen, R 1 is neither a-methylallyl nor a-methylpropargyl, in an aqueous medium to give the corresponding 2-R 1 -3-R 2 -4-hydroxy-2-cyclopentenone of the formula: wherein R 1 and R 2 are each as defined above.
Claim 2
Dependent Claim 119 words
A process for preparing cyclopentenolones which comprises treating a 4-hydroxy-4-R 2 -5-R l -2-cyclo- pentenone of the formula: wherein R 1 is an alkyl group having not more than 6 carbon atoms, an alkenyl group having not more than 6 carbon atoms, an alkynyl group having not more than 6 carbon atoms or a group of the formula: (in which R 3 is hydrogen, methyl or halogen) and R 2 is a hydrogen atom or a methyl group, provided that when R 2 is hydrogen, R 1 is neither a-methylallyl nor a-methylpropargyl, in an aqueous medium to give the corresponding 2-R 1 -3-R 2 -4-hydroxy-2-cyclopentenone of the formula: wherein R 1 and R 2 are each as defined above.
Claim 3
Dependent Claim 19 words
The process according to claim 1, wherein the treatment is carried out at a temperature of 20 to 200°C.
Claim 4
Dependent Claim 19 words
The process according to claim 1, wherein the treatment is carried out at a temperature of 120 to 200°C.
Claim 5
Dependent Claim 19 words
The process according to claim 1, wherein the treatment is carried out in the presence of a metal salt.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Maintenance schedule is calculated for granted US utility patents.

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag