Remarkable Difference in the Cycloaddition Reactivity between 2-(1-Trimethylsilyloxyvinyl)furan and -thiophene

Abstract

c f u r a n undergoes [ 4 + Z ] c y c l o a d d i t i o n r e a c t i o n w i t h e a s e , b u t thiophene does w i t h d i f f i c u l t y .' Alder r e a c t i o n of v i