Stereoselective Epoxidations and Electrophilic Additions to Partial Ergot Alkaloids and Conformationally-Fixed Styrenes. Experimental and Theoretical Modeling Evidence for the Importance of Torsional Steering as a Stereocontrol Element
摘要:
Partial ergot alkaloid substrates and related conformationally-fixed styrenes undergo epoxidation, osmium tetraoxide dihydroxylation, and hydrobromination with a level of stereoselectivity which cannot be explained by steric control but is consistent with electrophilic attack to minimize torsional strain. Force-field modeling is consistent with the importance of torsional steering as the dominant stereochemical control element.
Stereoselective Epoxidations and Electrophilic Additions to Partial Ergot Alkaloids and Conformationally-Fixed Styrenes. Experimental and Theoretical Modeling Evidence for the Importance of Torsional Steering as a Stereocontrol Element
摘要:
Partial ergot alkaloid substrates and related conformationally-fixed styrenes undergo epoxidation, osmium tetraoxide dihydroxylation, and hydrobromination with a level of stereoselectivity which cannot be explained by steric control but is consistent with electrophilic attack to minimize torsional strain. Force-field modeling is consistent with the importance of torsional steering as the dominant stereochemical control element.
A heteroannulation process for preparing piperidones and tetrahydropyridones by reacting an appropriately substituted enamine with an acryloyl derivative wherein a leaving group occupies the carbonyl; a process for cleaving a 1-phenylethyl group from an acylated amino group or an heterocyclic nitrogen atom adjacent to a carbonyl group, particularly that on the nitrogen atom of the products of the heteroannulation process, is also provided.
Stereoselective Epoxidations and Electrophilic Additions to Partial Ergot Alkaloids and Conformationally-Fixed Styrenes. Experimental and Theoretical Modeling Evidence for the Importance of Torsional Steering as a Stereocontrol Element
作者:Michael J. Martinelli、Barry C. Peterson、Vien V. Khau、Darrell R. Hutchison、M. Robert Leanna、James E. Audia、James J. Droste、Yun-Dong Wu、K. N. Houk
DOI:10.1021/jo00087a042
日期:1994.4
Partial ergot alkaloid substrates and related conformationally-fixed styrenes undergo epoxidation, osmium tetraoxide dihydroxylation, and hydrobromination with a level of stereoselectivity which cannot be explained by steric control but is consistent with electrophilic attack to minimize torsional strain. Force-field modeling is consistent with the importance of torsional steering as the dominant stereochemical control element.