918896-58-9Relevant academic research and scientific papers
Synthetic studies on Ecteinascidin-743: synthesis of building blocks through Sharpless asymmetric dihydroxylation and aza-Michael reactions
Chandrasekhar,Reddy, N. Ramakrishna,Rao, Y. Srinivasa
, p. 12098 - 12107 (2007/10/03)
A practical and an efficient synthesis of three building blocks of tetrahydroisoquinoline alkaloid Ecteinascidin-743 was accomplished, starting from readily available piperonal, 2-methyl anisole, and veratraldehyde. A combination of Vilsmeier-Haack reaction and Sharpless asymmetric dihydroxylation was employed for the synthesis of building blocks A and B whereas a Heck reaction in PEG-2000 and aza-Michael reactions were employed for the synthesis of building block C.
Diastereoselective Synthesis of Cularine Alkaloids via Enium Ions and an Easy Entry to Isoquinolines by Aza-Wittig Electrocyclic Ring Closure
Rodrigues, J. Augusto R.,Abramovitch, Rudolph A.,De Sousa, Joana D. F.,Leiva, Genaro C.
, p. 2920 - 2928 (2007/10/03)
In preliminary communications, we reported the diastereoselective synthesis of cularine and sarcocapnine via the intramolecular ring closure of nitrenium and oxenium ions, a new highly diastereoselective reductive methylation with (+)-8-phenylmenthyl chloroacetate followed by reduction with sodium borohydride, and a facile entry to the isoquinoline precursors by aza-Wittig electrocyclic ring closure. We now report the full details of the syntheses of (+)-O-demethylcularine, (+)-cularine, (+)-sarcocapnidine, (+)-sarcocapnine, and (+)-crassifoline and describe different methods of synthesis of their precursors.
