Hetero-Diels-Alder reactions of dimethyl 1-oxo-(E,E)-2,4-hexadienephosphonate with 2-alkylidene-1,3-dithianes

被引：12

作者：

Schuster, T

Evans, SA

机构：

[1] Laboratories of Chemistry, The University of North Carolina, Chapel Hill

来源：

PHOSPHORUS SULFUR AND SILICON AND THE RELATED ELEMENTS | 1995年 / 103卷 / 1-4期

基金：

美国国家科学基金会;

关键词：

Diels-Alder reactions; phosphonates; NMR; Lewis acid catalysis; pyrans;

D O I：

10.1080/10426509508027385

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

The cycloaddition reactions of dimethyl 1-oxo-(E,E)-2,3-hexadiene phosphonate (1) with 2-alkylidene-1,3-dithianes 4 and 5 gave [1]oxa-[7,11]dithiaspiro-[5,5]undecene-2-phosphonate derivatives. The reactions were responsive to electrophilic assistance by the solvent as well as 'conventional' Lewis Acid catalysis. The structural constitutions and preferred conformations of these pyran derivatives were established by NMR spectroscopy as well as by the X-ray crystallographic determination of a key derivative. In addition to E- to Z-double bond isomerization reactions in 1 and acyl chloride 2, alpha-acyl phosphonate 1 underwent thermal isomerization to dimethyl 2H-pyran-6-phosphonate (6).

引用

页码：259 / 271

页数：13

共 26 条

[1] The modes of addition to conjugated unsaturated systems Part II The reduction of conjugated unsaturated acids by metals dissolving in aqueous media [J].