Diels-Alder reaction of 4,6-dihydrothieno(3,4-c)furan-5,5-dioxide with quinones: Stereoselective synthesis of quinone-annelated 2,3-bis(methylene)-7-oxabicyclo(2.2.1)heptanes.
作者:Takayoshi SUZUKI、Kan KUBOMURA、Hiroaki TAKAYAMA
DOI:10.1248/cpb.39.2164
日期:——
4, 6-Dihydrothieno[3, 4-c]furan-5, 5-dioxide (1), a novel precursor of a bis-diene, reacts with quinones to afford the normal Diels-Alder adducts, the quinone-annelated 2, 3-bis (methlene)-7-oxabicyclo[2.2.1]-heptane derivatives. Promising building blocks(3b and 5) for the synthesis of the antineoplastic antibiotics are prepared by this method.
Furan-fused 3-sulfolene as a novel building block: intermolecular Diels–Alder reactions of 4H,6H-thieno[3,4-c]furan 5,5-dioxide
作者:Takayoshi Suzuki、Kan Kubomura、Hiroaki Takayama
DOI:10.1039/a604600b
日期:——
A furan-fused 3-sulfolene
4H,6H-thieno[3,4-c]furan 5,5-dioxide 1, can be
used as a bis-diene, reacting sequentially with a variety of dienophiles to
construct four types of skeleton, depending on the dienophile and the
reaction conditions. The 3-sulfolene moiety of the furansulfolene not only
functions as the s-cis-diene part in DielsâAlder reactions,
but also extends the range of the DielsâAlder reactions of the furan
moiety with various dienophiles through its desulfonylation to form the
s-cis-diene.