Patent US3576887A successfully refreshed from Google Patents.
US3576887A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of oxaphenanthrenes and intermediates therefor
Assignee: Wyeth LLC
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Filing: 1967-05-01
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Granted: 1971-04-27
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Expires: 1987-05-01
Abstract
Abstract 6,6-DIALKYLTETRA-HYDRO- AND HEXAHYDRO-6H-DIBENZO (B,D) PYRANS (I) ARE OBTAINED BY CYCLODEHYDRATING A 1-(1''-HYDROXY)ALKYL-2-O-HYDROXYPHENYLCYCLOHEXANE OR -ONE (III). COMPOUNDS (III) ARE OBTAINED BY TREATING A 2-O-ALKOXY-PHENYLCYCLOHEXANE- OR ENECARBOXYLIC ACID OR ESTER (II) WITH A GRIGNARD REAGENT. ENANTIOMORPHIC COMPOUNDS (I), PARTICULARLY, (-) -$8-TETRAHYDROCANNABINOL, A BIOLOGICALLY ACTIVE, ASYMMETRIC CONSTITUENT OF HASHISH, ARE PREPARED BY CYCLIZING THE CORRESPONDING ENANTIOMORPHIC COMPOUNDS (III).
Inventors
- 👤 Gordon A Hughes
- 👤 Timothy Y Jen
- 👤 Herchel Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:20
CPC Classifications
C; C07; C07C; C07C39/00; C07C39/23; C07D; C07D311/00; C07D311/02; C07D311/78; C07D311/80; C07C2601/00; C07C2601/12; C07C2601/16
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-26 | 1974-10-26 | 1975-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-26 | 1978-10-26 | 1979-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-26 | 1982-10-26 | 1983-04-27 | $7700.00 | Window Closed / Lapsed |