Asymmetric synthesis of 4-amino-3,4-dihydro-2,2-dimethyl-2H-1-benzopyrans

Add time:08/22/2019    Source:sciencedirect.com

Highly enantioselective reduction of 3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-4-ones 3 a-e by BH3 was achieved in the presence of catalytic amounts of Corey's oxazaborolidine 4 to afford the corresponding 3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-4-ols2a-e in quantitative yields. These benzopyran-4-ols 2a-e were converted into the chiral 4-amino-3,4-dihydro-2,2-dimethyl-2H-1-benzopyrans 1a-e by mesylation, followed by introduction of an azide group by tetra-n-butyl-ammonium azide, and finally by reduction of the azide 6 with triphenylphosphine under very mild conditions without loss of stereo information.

We also recommend Trading Suppliers and Manufacturers of 2H-1-Benzopyran-8-aMine, 3,4-dihydro- (cas 113722-25-1). Pls Click Website Link as below: cas 113722-25-1 suppliers

Prev:New R/S-3,4-dihydro-2,2-dimethyl-2H-1-benzopyrans as KATP channel openers: Modulation of the 4-position
Next:Synthesis, biological activity and quantitative structure-activity relationships of N-substituted-3,4-dihydro-2H-1-benzopyran derivatives)