Intramolecular ionic Diels-Alder reactions of alpha-acetylenic acetals.
The intramolecular ionic Diels-Alder reaction of alpha-acetylenic acetals as a precursor of the propargyl cation has been investigated in the presence of Lewis acids and in protic acids. The reaction of diene-tethered alpha-acetylenic acetals (1-2) with formic acid yielded the regioselective intramolecular ionic Diels-Alder reaction products, bicyclodienal (9) and bicyclodienone (11) derivatives, in good yields.
Shim
Seung-Bo
SB
School of Chemistry, Seoul National University, Seoul 151-742, Korea.
Ko
Yoon-Joo
YJ
Yoo
Byeong-Wook
BW
Lim
Chang-Keun
CK
Shin
Jung-Hyu
JH