Benzothiazines in Organic Synthesis. The Preparation of Enantiomerically Pure 4-Substituted Quinolones
摘要:
3,4-Dihydroquinolin-2(1H)-ones have potential biological and pharmacological significance. Enantiomerically pure benzothiazines, readily available via an intramolecular addition of a sulfoximine-stabilized carbanion to an alpha,beta-unsaturated ester, could be used as templates for making a series of enantiomerically pure 3,4-dihydroquinolin-2(1H)-ones under mild conditions.
The Intramolecular, Stereoselective Addition of Sulfoximine Carbanions to α,β-Unsaturated Esters
摘要:
ortho-Bromocinnamates can be coupled with methyl phenylsulfoximine to afford N-arylsulfoximines in excellent yield. Treatment of these products with an amide base results in a completely stereoselective cyclization to afford enantiomerically pure benzothiazines. This reaction is stereospecific.