US4914217A
Expired / Lapsed
US
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Asymmetric synthesis of natural vitamin E
Assignee: Hoffmann La Roche Inc
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Filing: 1989-05-15
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Granted: 1990-04-03
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Expires: 2009-05-15
Abstract
Abstract An asymmetric synthesis for Vitamin E in an optically active pure form for 4-(2,5-diloweralkanoyloxy)-3,4,6-trimethylphenyl-butan-2-one and intermediates therein.
Inventors
- 👤 Ka-Kong Chan
- 👤 Gabriel G. Saucy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:37
CPC Classifications
C; C07; C07D; C07D311/00; C07D311/02; C07D311/04; C07D311/58; C07D311/70; C07D311/72; C07C; C07C46/00; C07C46/02; C07C46/06; C07C46/10; C07C50/00; C07C50/26; C07C50/28
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
40 words
A process for converting a quinone of the formula: ##STR21## wherein R 11 is tosyl or mesyl, lower alkanoyl into a compound of the formula: ##STR22## comprising reducing said quinone with an alkali metal hydride reducing agent, or zinc dust.
Claim 2
Dependent Claim
40 words
A process for converting a quinone of the formula: ##STR21## wherein R 11 is tosyl or mesyl, lower alkanoyl into a compound of the formula: ##STR22## comprising reducing said quinone with an alkali metal hydride reducing agent, or zinc dust.
Claim 3
Dependent Claim
16 words
The process of claim 1 wherein said reducing agent is a sodium borohydride, or zinc dust.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1993-04-02 | 1993-10-02 | 1994-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-02 | 1997-10-02 | 1998-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-02 | 2001-10-02 | 2002-04-03 | $7700.00 | Window Closed / Lapsed |