Chemistry with Lithium Amide: Enantiotopic Group & Face Selective Reactions
Seven interesting chiral amines have been synthesized and applied into the enolate chemistry of two interesting precursors of synthesis of natural products: 1,4- cyclohexanedione monoethylene ketal and tropinone.
The aldol reaction between the lithium enolate of 1,4-cyclohexanedione monoethylene ketal and benzaldehyde demonstrated the high diastereoselectivity (up to 98% de) and the moderate to high enantioselectivity (up to 75% ee) induced by those chiral lithium amides. On the other hand, high diastereoselectivity (up to 100% de) and the low enantioselectivity were obtained from the aldol reaction of tropinone enolate with benzaldehyde differentiated by chiral lithium amides with extra electron donor atoms.
An analysis method to determine enantioselectivity from racemic ?-hydroxytropinone was developed. That will, no doubt, benefit the further enantioselective ?-hydroxylation reaction of tropinone.
School:University of Saskatchewan
School Location:Canada - Saskatchewan
Source Type:Master's Thesis
Keywords:lithium amide enantiotopic group face selective
Date of Publication:12/03/2007