Chemoenzymatic synthesis of enantiomerically enriched 2-oxobicyclo[m.1.0]alkan-3-yl acetate derivatives


Thesis Type: Postgraduate

Institution Of The Thesis: Middle East Technical University, Faculty of Arts and Sciences, Department of Chemistry, Turkey

Approval Date: 2005

Thesis Language: English

Student: Selin Atlı

Supervisor: CİHANGİR TANYELİ

Abstract:

a,β-Unsaturated cyclic ketones were selectively oxidized on a'- positions using Mn(OAc)3 and Pb(OAc)4, respectively. The resultant racemic a'-acetoxylated substrates were resolved into corresponding enantiomerically enriched a'-hydroxylated and a'-acetoxylated compounds via PLE hydrolysis. a'-Hydroxylated compounds are racemized quickly, so they were acetylated with acetyl chloride and pyridine in situ to give the corresponding a'-acetoxylated compounds. Resultant a'-acetoxy a,β-unsaturated cyclic ketones reacted with excess amount of diazomethane under the catalsts of Pd(OAc)2 to give the resulting bicyclic diastereomeric products. At the end of the experiment, Enantiomeically enriched 2-oxobicyclo[3.1.0]hexan-3-yl acetate and 2-oxobicyclo[4.1.0]heptan-3-yl acetate were chemoenzymatically synthesized.