392663-00-2Relevant academic research and scientific papers
Total synthesis and structural elucidation of azaspiracid-1. Construction of key building blocks for originally proposed structure
Nicolaou,Pihko, Petri M.,Bernal, Federico,Frederick, Michael O.,Qian, Wenyuan,Uesaka, Noriaki,Diedrichs, Nicole,Hinrichs, Juergen,Koftis, Theocharis V.,Loizidou, Eriketi,Petrovic, Goran,Rodriquez, Manuela,Sarlah, David,Zou, Ning
, p. 2244 - 2257 (2007/10/03)
Syntheses of the three key building blocks (65, 98, and 100) required for the total synthesis of the proposed structure of azaspiracid-1 (1a) are described. Key steps include a TMSOTf-induced ring-closing cascade to form the ABC rings of tetracycle 65, a neodymium-catalyzed internal aminal formation for the construction of intermediate 98, and a Nozaki-Hiyama-Kishi coupling to assemble the required carbon chain of fragment 100. The synthesized fragments, obtained stereoselectively in both their enantiomeric forms, were expected to allow for the construction of all four stereoisomers proposed as possible structures of azaspiracid-1 (1a-d), thus allowing the determination of both the relative and absolute stereochemistry of the natural product.
Synthesis of the ABCD ring system of azaspiracid
Nicolaou,Qian, Wenyuan,Bernal, Federico,Uesaka, Noriaki,Pihko, Petri M.,Hinrichs, Jrgen
, p. 4068 - 4071 (2007/10/03)
Previously attempted spirocyclizations to form the ABCD ring system of azapiracid (1) have proven unsuccessful owing to the anomeric effects that favor the formation of the undesired 13S diastereomer. By the use of a hydrogen bond donor as an auxiliary gr
