Lynch, S. M. ; Bur, S. K.; Padwa, A. Intramolecular Amidofuran Cycloadditions across an Indole π-Bond: An Efficient Approach to the Aspidosperma and StrychnosABCE Core. Org. Lett. 2002, 4 (26): 4643. PMID 12489950. doi:10.1021/ol027024q.
Lynch, S. M. ; Bur, S. K.; Padwa, A. Intramolecular Amidofuran Cycloadditions across an Indole π-Bond: An Efficient Approach to the Aspidosperma and StrychnosABCE Core. Org. Lett. 2002, 4 (26): 4643. PMID 12489950. doi:10.1021/ol027024q.