Functional group manipulation of some complex organic molecules /
There is a constant demand for new methods by which
| Main Author: | |
|---|---|
| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1994.
|
| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=741966211&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | There is a constant demand for new methods by which functional groups of organic molecules can be manipulated to acheive a synthetic goal. A desirable method should be selective, efficient and carried out under mild conditions. the concept of functional group manipulation was applied to the synthesis of ambrox (a valuable fragrance material) from sclareol, a diterpenoid readily available from natural sources. Several selective and efficient oxidation reactions of sclareol were developed as the key synthetic step in the synthesis of ambrox. Ambrox was prepared from sclareol effectively in three steps. The Barton-McCombie deoxygenation reaction is an example of useful functional roup manipulation. A hydroxyl function, (-OH) can be reduced to the 9 corresponding hydrocarbon by the deoxygenation reaction. Some complex, polyfunctional and sterically hindered hydroxyl groups can be deoxygenated by this method while other methods fail. Barton-McCombie deoxygenation was not applied successfully to tertiary alcohols because the intermediate tertiary thionocarbonyl derivatives required were difficult to prepare and unstable under the reaction conditions, causing spontaneous elimination. An improved method for the preparation of tertiary xanthates from tertiary alcohols was developed such that they can be deoxygenated under mild conditions. An improved method to derivative hydroxyl functionalities to N-substituted selenocarbarnates was developed and shown to be versatile and efficient for primary, secondary and tertiary alcohols. The reagents required for the derivatization, selenoisocyanates, were found to be easily prepared by a novel one-pot procedure from formamides. The reactivity of the new selenocarbamates was studied. |
|---|---|
| Item Description: | Vita. "Major Subject: Chemistry". |
| Physical Description: | x, 119 leaves ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references. |