Synthesis of the C1–C21 Domain of Azaspiracids-1 and −3
摘要:
An efficient synthesis of the C1-C21 fragment of azaspiracids-1 and -3 is described. This features a Nozaki-Hiyama-Kishi reaction to couple the AB and CD ring precursors and formation of the THF-fused ABCD trioxadispiroketal system under thermodynamic conditions.
Synthesis of the C1–C21 Domain of Azaspiracids-1 and −3
摘要:
An efficient synthesis of the C1-C21 fragment of azaspiracids-1 and -3 is described. This features a Nozaki-Hiyama-Kishi reaction to couple the AB and CD ring precursors and formation of the THF-fused ABCD trioxadispiroketal system under thermodynamic conditions.
作者:Nathaniel T. Kenton、Daniel Adu‐Ampratwum、Antony A. Okumu、Zhigao Zhang、Yong Chen、Son Nguyen、Jianyan Xu、Yue Ding、Pearse McCarron、Jane Kilcoyne、Frode Rise、Alistair L. Wilkins、Christopher O. Miles、Craig J. Forsyth
DOI:10.1002/anie.201711006
日期:2018.1.15
A convergent and stereoselective total synthesis of the previously assigned structure of azaspiracid‐3 has been achieved by a late‐stage Nozaki–Hiyama–Kishi coupling to form the C21−C22 bond with the C20 configuration unambiguously established from l‐(+)‐tartaric acid. Postcoupling steps involved oxidation to an ynone, modified Stryker reduction of the alkyne, global deprotection, and oxidation of