SYNTHESIS OF ENANTIOPURE PYRROLO[3,4-cPYRAZOLE DERIVATIVES VIA INTRAMOLECULAR CYCLOADDITION OF HOMO-CHIRAL NITRILIMINES
摘要:
Intramolecular cycloaddition of homochiral nitrilimines 8 was exploited to obtain enantiopure pyrrolo[3,4-c]pyrazole derivatives 9 and 10 with high overall yields.
Cyclisation of (R)- and (S)-N-allyl-N-(1-phenylethyl) methoxycarbonylacetamide mediated by Mn(III): Preparation and structural assignment of 3-aza-2-oxobicyclo[3.1.0]hexanes
摘要:
(R)- and (S)-N-allyl-N-(I-phenylethyl)methoxycarbonylacetamide, 5 and 6, underwent oxidative cyclisation mediated by Mn(III), to give easily separable diastereomeric mixtures of 3-aza-2-oxobicyclo[3.1.0]hexanes 8a,b and 9a,b, respectively, whose structures were assigned on the basis of H-1 NMR spectra and then confirmed by X-ray diffraction analysis of the derivatives 11b and 14. Copyright (C) 1996 Elsevier Science Ltd.