| Budget Amount *help |
¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 1999: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1998: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Research Abstract |
The steric of the photocyclization reaction of N-alkylfuran-2-carboxyanilides (1) to optically active trans-dihydrofuran derivatives (2) was controlled by carrying out the reaction in inclusion crystals (4) with optically hosts (3) derived from tartaric acid. The mechanism of the steric course of the photoreaction of 1 in 4 was studied by X-ray structural analysis of 4. In some cases, the steric course of the photoreaction was different depending on whether 4 was prepared by recrystallization or by mixing 1 and 3.
Enantioselective reaction of N-methyl-N-phenyl-3-amino-2-cyclohexen-1-one derivatives to the corresponding N-methylhexahydro-4-carbazolones has bcen accomplised by photolysis in a water suspension of 1:1 inclusion compounds of the starting material with optically active host compounds derived from tartaric acid. 3-(N-Methylanilino)-2,5,5-trimethyl-2-cyclohexen-1-One formed two kinds of dimorphous crystals, and one of these gave an optically active carbazolone derivative by pho
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tolysis, but the other one was photochemically inert. X-ray structure analysis showed that two reaction centers, the phenyl and cyclohexenone groups of the reactant, are located in close and distant positions respectively in these two inclusion compounds.
It has been found that the achiral molecules of N,N-diisopropyl phenylglyoxylamide crystallize in a chiral space group and are transformed to almost optically pure β-lactam when the powdered sample is irradiated with UV light. In order to analyze the mechanism of the asymmetric induction, the chlorine atom was substituted to the phenyl ring and the absolute crystal structures of the reactant glyoxylamide and the β-lactam were determined by using X-ray anomalous scattering. N,N-diisopropyl(3-methyl)phenylglyoxylamide has a methyl group instead of the chlorine atom. The powdered samples was irradiated with 400 W high-pressure Hg lamp for 10 h. The corresponding almost optically pure β-lactam was produced : 63% chemical yield and 91% ee. In order to examine the mechanism, crystal structure of this compound was determined.
We have studied the optical resolution of various racemic guest compounds by inclusion crystallization with optically active host compounds. We have also reported that efficient inclusion crystallization can be achieved simply by mixing powdered crystalline host and a hydrophobic guest compound in hexane or water. Furthermore, when combined with a distillation procedure, racemic compounds could be separated into enantiomers by fractional distillation in the presence of optically active host compounds. We have now found that optically active compounds were obtained efficiently by combination of the preparation of racemic compounds and optical resolution by inclusion complexation using a chiral host compound in a water suspension medium. Less
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