Total regio- and stereoselective synthesis of perhydropyrrolo[3,4-c]pyrazole derivatives by [3+2] intramolecular dipolar cycloaddition reaction on chiral perhydro-1,3-benzoxazines

摘要

Reaction of N-acyl-N'-methyl- or N-acyl-N'-phenylhydrazines with chiral 3-allyl-2-formylperhydro-1,3-benzoxazines form azomethine imines that cyclize to give perhydropyrrolo[3,4c]pyrazole derivatives. The dipolar cycloaddition was totally regio-and stereoselective yielding a single diastereoisomer. The reaction conditions and the yields of the final compounds are dependent on the substitution pattern of the olefinic bond. [References: 33]