Files in this item
|(no description provided)|
|Title:||The Synthesis of Lauraceae Lactones: Obtusilactones, Litsenolides, and Mahubanolides|
|Author(s):||Rollinson, Susan Lynn Wells|
|Department / Program:||Chemistry|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||Phenylselenenyl esters (methyl esters of 2-phenylselenenylhexadecanoic, 2-phenylselenenyloctadecanoic, and 2-phenylselenenyl-13-tetradecadienoic acids) were used as acrylate (alpha)-anion synthons in aldol addition reactions. The last acid above, bearing the terminal double bond, was synthesized by displacing the (omega)-bromide from methyl 11-bromo-2-phenylselenenylundecanoate by allyllithium. The other (alpha)-phenylselenenyl esters were made by quenching their lithium enolates with phenylselenenyl chloride. Addition to acrolein, followed by oxidation and selenoxide elimination gave the corresponding (alpha),(beta)-unsaturated esters bearing a 1-hydroxy-2-propenyl group at the (alpha)-carbon. Similarly, addition to propargylaldehyde followed by oxidative work-up gave the corresponding (alpha),(beta)-unsaturated esters bearing a 1-hydroxy-2-propynyl group at the (alpha)-carbon.
Hydrolysis of the olefinic esters to the corresponding carboxylic acids followed by lactonization (iodine or phenylselenenyl chloride) and hydrogenolysis (tri-n-butyltin hydride) gave (alpha)-alkylidene-(beta)-hydroxy-(gamma)-methyl-(gamma)-butyrolactones which are known natural products (litsenolides, dihydromahubanolides). Hydrolysis of the acetylenic esters to the corresponding carboxylic acids, followed by lactonization (mercuric trifluoroacetate or sodium bicarbonate) gave (alpha)-alkylidene-(beta)-hydroxy-(gamma)-methylene (gamma)-butyrolactones which are also known natural products (obtusilactones, mahubanolides). One of these, obtusilactone, the (gamma)-methylene lactone with the (alpha)-11-dodecenylidene moiety, has been reported to be cytotoxic.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1980.
|Date Available in IDEALS:||2014-12-13|