High, Exoselective Diels–Alder Reaction in 5.0M Lithium Perchlorate in Diethyl Ether Medium: Efficient Synthesis of Novel Heterocyclic Derivatives Containing a Spirobicyclo[2.2.1]heptane System
作者:M Shanmugasundaram、R Raghunathan
DOI:10.1016/s0040-4020(00)00433-6
日期:2000.7
Exocyclic arylidene derivatives have been used as dienophiles in Diels–Alder reactions with cyclopentadiene. A series of novel heterocyclic derivatives containing the spiro bicyclo[2.2.1]heptane system is the outcome of such reactions. The reactions proceed with high exoselectivity in the presence of 5.0 M LPDE medium.
在Diels-Alder与环戊二烯的反应中,环外亚芳基衍生物已被用作亲二烯体。含有螺双环[2.2.1]庚烷系统的一系列新型杂环衍生物是这种反应的结果。在5.0 M LPDE介质存在下,反应以高选择性进行。
1,3-Dipolar Cycloaddition of 3-Arylidenechromanone -1-thiochromanone and -flavanone: Regio- and Stereoselective Formation of Spiroheterocycles
The cycloaddition of nitrile oxides, nitrones, and nitrile imines to 3-arylidenechromanone (1), -flavanone (5), -1-thiochromanone (2) and -1-tetralone (3) proceeds regio-and stereoselectively under the formation of spiro-substituted isoxazole and pyrazole derivatives.
Wroblewski; Karolczak, Polish Journal of Chemistry, 1999, vol. 73, # 7, p. 1191 - 1202
作者:Wroblewski、Karolczak
DOI:——
日期:——
Synthesis and conformational analysis of some spiropyrazoline isomers
that this cycloaddition is regio- and stereoselective affording trans- and cis- spiro-1-pyrazolines. Spiro-1-pyrazolines were converted into spiro-2-pyrazolines on acid-catalysed isomerization. Conformation and relative configuration of compounds prepared has been elucidated by various one- and two-dimensional n.m.r. methods.