Stereoselective Synthesis of (2<i>E</i>,4<i>Z</i>)-Dienamides Employing (Triphenylphosphoranylidene)ketene
作者:Steffen Pachali、Christine Hofmann、Georg Rapp、Rainer Schobert、Angelika Baro、Wolfgang Frey、Sabine Laschat
DOI:10.1002/ejoc.200900176
日期:2009.6
reaction between ylide Ph3PCCO, amines and aldehydes is known to afford selectively (E)-α,β-unsaturated amides. We applied a variant of this methodology to the preparation of (2E,4Z)-dienamides 11 utilizing the phosphonium salt formation from ethyl 5-aminopentanoate hydrochloride and Ph3PCCO followed by deprotonation with DBU and a Wittig olefination of the corresponding ylide with various (Z)-α,β-unsaturated
已知叶立德 Ph3PCCO、胺和醛之间的三组分反应可选择性地提供 (E)-α,β-不饱和酰胺。我们应用这种方法的变体来制备 (2E,4Z)-二烯酰胺 11,利用 5-氨基戊酸乙酯盐酸盐和 Ph3PCCO 形成的鏻盐,然后用 DBU 去质子化,并用各种 (Z) -α,β-不饱和醛 10. (2E,4Z)-二烯酰胺 11 的分离产率高达 80%。在反应过程中,起始醛 10 的 (Z)-构型保持不变。 (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)