Studies toward the Total Synthesis of Axinellamine and Massadine
作者:Rasapalli Sivappa、Nora M. Hernandez、Yong He、Carl J. Lovely
DOI:10.1021/ol0711568
日期:2007.9.1
Intramolecular Diels-Alder reactions of several N-O linked 4-vinylimidazole dimers provide the expected adduct in moderate to good yield as a single, all trans stereoisomer, along with smaller amounts of the inverse electron demand adduct. Oxidative rearrangement of the cycloadducts occurs on treatment with Davis' reagent, providing a single spiro imidazolone in good yield and with excellent levels of stereocontrol albeit epimeric at the spiro center found in axinellamine and massadine.
Palladium-catalyzed substitution reactions of 4-allylimidazole derivatives
作者:Pasupathy Krishnamoorthy、Rasapalli Sivappa、Hongwang Du、Carl J. Lovely
DOI:10.1016/j.tet.2006.05.090
日期:2006.11
required an efficient method for conducting substitutionreactions of allylic alcohols derived from urocanic acid. While in some cases this could be accomplished quite readily by classical nucleophilic substitution, it was complicated by allylic transposition in others. Application of Pd-catalyzed π–allyl chemistry provided a convenient solution, giving substitution without allylic transposition. Herein