| Budget Amount *help |
¥5,500,000 (Direct Cost: ¥5,500,000)
Fiscal Year 1988: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1987: ¥4,800,000 (Direct Cost: ¥4,800,000)
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| Research Abstract |
Chiral b-hydroxysulfones (I), -hydroxysulfones (II), and -hydroxy-nitrocompounds (III) were prepared in 100% e.e. by Baker's yeast reduction of the corresponding ketones. Reduction of chiral -ketosulfoxides with diisobutylaluminum hydride produced diastereoisomeric -hydroxysulfoxides (IV) in 100% e.e. The reaction of the dianions of I and IV with alkylating reagents or carbonyl compounds lead to the stereoselective carbon-carbon-carbon bond formation. While the intramolecular chelation of a metal cation may play an important role in the reaction of IV, the coordinatio of solvents molecules with a metal cation may be predominat in the dianion of I.
In the reactions of these dianions the carbonyl compounds attack the carbanion on the side of a metal cation, whereas the approach of the alkylating reagents was found to be governed by the steric effects regardless of the cation. In the dianion of IV the configurational interconversion of the carbanion took place, and the intramolecular chelation of a metal cation with the adjacent group is assumed to play an important role in the conversion.
From I-IV many chiral compounds such as -, -lactones, tetrahydrofurans, and allylic alochols were synthesized in 100% e.e., that is to say, I-IV are very useful chiral building blocks.
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