Phosphine-catalyzed synthesis of 6-substituted 2-pyrones: Manifestation of E/Z-isomerism in the zwitterionic intermediate

被引：161

作者：

Zhu, XF ^{[1
]}

Schaffner, AP ^{[1
]}

Li, RC ^{[1
]}

Kwon, O ^{[1
]}

机构：

[1] Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA

来源：

ORGANIC LETTERS | 2005年 / 7卷 / 14期

关键词：

D O I：

10.1021/ol050946j

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

We report a one-step phosphine-catalyzed annulation between aldehydes and ethyl allenoate to form 6-substituted 2-pyrones. The mechanistic rationale for this reaction requires explicit discussion of the EIZ-isomerism of the zwitterionic intermediate formed by the addition of a phosphine to the allenoate. Sterically demanding trialkylphosphines facilitate the shift of equilibrium toward the E-isomeric zwitterion and lead to the formation of 6-substituted 2-pyrones. Various aromatic as well as aliphatic aldehydes undergo the transformation in moderate to excellent yield.

引用

页码：2977 / 2980

页数：4

共 75 条

[71] Abnormal aza-Baylis-Hiliman reaction of N-tosylated imines with ethyl 2,3-butadienoate and penta-3,4-dien-2-one [J].

Zhao, GL ;

Huang, JW ;

Shi, M .

ORGANIC LETTERS, 2003, 5 (24) :4737-4739

[72] Asymmetric [3+2] cycloaddition of 2,3-butadienoates with electron-deficient olefins catalyzed by novel chiral 2,5-dialkyl-7-phenyl-7-phosphabicyclo[2.2.1]heptanes [J].

Zhu, GX ;

Chen, ZG ;

Jiang, QZ ;

Xiao, DM ;

Cao, P ;

Zhang, XM .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1997, 119 (16) :3836-3837

[73] Phosphine-catalyzed synthesis of 1,3-dioxan-4-ylidenes [J].

Zhu, XF ;

Henry, CE ;

Wang, J ;

Dudding, T ;

Kwon, O .

ORGANIC LETTERS, 2005, 7 (07) :1387-1390

[74] An expedient phosphine-catalyzed [4+2] annulation: Synthesis of highly functionalized tetrahydropyridines [J].

Zhu, XF ;

Lan, J ;

Kwon, O .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2003, 125 (16) :4716-4717

[75]

ZHU XF, 2005, IN PRESS TETRAHEDRON

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