144061-37-0Relevant articles and documents
SYNTHESIS OF FURO-FURANS BY REARRANGEMENT OF 4-ACETYLPYRANS
Celli, Angela M.,Scotton, Mirella,Sega, Alessandro
, p. 5883 - 5900 (1992)
The hetero-Diels-Alder reaction of 1-oxabutadienes 1a-c bearing electron-withdrawing groups with ethyl vinyl ether and 2,3-dihydrofuran gave the functionalized 5,6-dihydro-4H-pyrans 2a-c, 4c and 4H-4a,5,6,6a-tetrahydrofuropyrans 5a-c and 6c.Cycloadducts 2a and 4c easily rearranged to furofurans 3a, 3c and 9c and cycloadducts 5a and 6c to difurofurans 7a, 7c and 8c.The stereochemistry of the compounds 5c and 7a was determined by single crystal X-ray analysis.Relative configurations of the other compounds were established by nOe data.Some aspects of the reaction mechanisms are discussed. Key Words: furo-furans, furo-pyrans, hetero-Diels-Alder, nOes.