| Budget Amount *help |
¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 2000: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1999: ¥2,300,000 (Direct Cost: ¥2,300,000)
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| Research Abstract |
The stereoselective construction of fused heterocycles was developed by tandem transetherification/intramolecular hetero Diels-Alder reaction as new type of intramolecular hetero Diels-Alder reaction. Furthermore the high enantioselective tandem reaction of activated bidentate enone with δ, ε-unsaturated alcohols was achieved by using cationic C2-symmetric chiral catalyst bearing bis(oxazoline). The following results were obtained.
1) Alkoxy-substituted unsaturated carbonyl compounds such as methoxy-methyleneacetylacetone, butoxymethylenecyanoacetaldehyde, and methyl (E)-4-methoxy-2-oxo-3-butenoate, underwent stereoselective intramolecular hetero Diels-Alder reaction to afford corresponding hydropyranopyrans in the presence of δ, ε-alkenyl alcohols under thermal conditions. The reactions involve the transetherification process between alkoxy-substituted unsaturated carbonyl compounds and δ, ε-alkenyl alcohols as the key step. 2) These tandem reactions also proceeded with sec- and tert-δ, ε-alkenyl alcohols 3) With E, Z-unsaturated alcohols, the reaction proceed stereospecificly to provide correspoding adducts. 4) This tandem reaction proceeds stereoselectively under mild conditions in the presence of catalytic amount of Lewis acid. 5) This tandem reaction proceed in one flask. Furthermore the tandem reaction of bidentate enone such as methyl (E)-4-methoxy-2-oxo-3-butenoate with δ, ε-alkenyl alcohols proceeds in high enantioselectivity (over 97% ee) to afford corresponding optically active hydropyranopyrans in the presence of C2-symmetric (S,S)-tert-butyl-bis (oxazolynyl) Cu (SbF6) 2 as chiral Lewis acid.
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