Enantiopure furo[3,4-c]pyrazole derivatives by intramolecular nitrilimine cycloaddition: a stereoselectivity rationale based upon MP2 calculations
摘要:
Silver carbonate treatment of hydrazonoyl chloride 4 promoted the in situ generation of the corresponding nitrilimine bearing a stereocentre at the alpha-position of the ethylenic dipolarophile. Intramolecular cycloaddition of the latter intermediate involves the formation of 4-(S)-methyl-6-oxo-3,3a,4,5-tetra hydro-furo[3,4-c]pyrazole derivatives with very good yield and diastereoselectivity. Full rationalization of the experimentally observed stereoselectivity has been pursued by means of MP2 calculations. (C) 2008 Elsevier Ltd. All rights reserved.
Enantiopure furo[3,4-c]pyrazole derivatives by intramolecular nitrilimine cycloaddition: a stereoselectivity rationale based upon MP2 calculations
摘要:
Silver carbonate treatment of hydrazonoyl chloride 4 promoted the in situ generation of the corresponding nitrilimine bearing a stereocentre at the alpha-position of the ethylenic dipolarophile. Intramolecular cycloaddition of the latter intermediate involves the formation of 4-(S)-methyl-6-oxo-3,3a,4,5-tetra hydro-furo[3,4-c]pyrazole derivatives with very good yield and diastereoselectivity. Full rationalization of the experimentally observed stereoselectivity has been pursued by means of MP2 calculations. (C) 2008 Elsevier Ltd. All rights reserved.
Enantiopure furo[3,4-c]pyrazole derivatives by intramolecular nitrilimine cycloaddition: a stereoselectivity rationale based upon MP2 calculations
作者:Giorgio Molteni、Alessandro Ponti
DOI:10.1016/j.tetasy.2008.05.007
日期:2008.6
Silver carbonate treatment of hydrazonoyl chloride 4 promoted the in situ generation of the corresponding nitrilimine bearing a stereocentre at the alpha-position of the ethylenic dipolarophile. Intramolecular cycloaddition of the latter intermediate involves the formation of 4-(S)-methyl-6-oxo-3,3a,4,5-tetra hydro-furo[3,4-c]pyrazole derivatives with very good yield and diastereoselectivity. Full rationalization of the experimentally observed stereoselectivity has been pursued by means of MP2 calculations. (C) 2008 Elsevier Ltd. All rights reserved.