First enantioselective total synthesis of neocarazostatin B, determination of its absolute configuration and transformation into carquinostatin A

R Czerwonka, KR Reddy, E Baum…

Index: Czerwonka, Regina; Reddy, Kethiri R.; Baum, Elke; Knoelker, Hans-Joachim Chemical Communications, 2006 , # 7 p. 711 - 713

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Citation Number: 36

Abstract

Scheme 2 Synthesis of the (R)-arylamine 10. Reagents and conditions: (a) tBuPh 2 SiCl, Et 3 N, reflux, 2 d, 98%; (b) 1. nBuLi, TMEDA, Et 2 O, 25 °C; 2. MeI, −78 °C to 25 °C, 96%; (c) NBS, MeCN, 25 °C, 100%; (d) tBuLi, THF, (R)-(+)-propene oxide, −78 °C, 91%; (e) TBAF, THF/H 2 O, 25 °C, 100%; (f) Ac 2 O, Et 3 N, DMAP, CH 2 Cl 2 , 25 °C, 98%; (g) fuming HNO 3 /HOAc, 25 °C, 77%; (h) H 2 , Pd/C, MeOH, 25 °C, 100%. ... Protection of guaiacol (6) as ...