| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2003: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2002: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Research Abstract |
In this research, the following results have been obtained during the two years.
Stereocontrolled synthesis of trisusbtituted alkene and conjugated trisubstituted diene
(1)Sonogashira coupling of 1,1-dibromo-1-alkene in the presence of Pd catalyst gave (Z)-bromoenyne with excellent stereo-selectivity in good yield. On the other hand, Kumada-Tamao-Corriu coupling of l,1-dibromo-1-alkene with trimethylmethylmagnesium chloride in the presence of Ni catalyst also gave (Z)-1-dibromo-1-trimethylsilylmethylalkene with excellent, stereo-selectivity in good yield.
(2)The second Sonogashira coupling reaction of (Z)-3-bromo-1-trimethylsilylenyne gave trisubstituted enyne stereoselectively. The selectivity was depended on the solvent. Complete geometric inversion was observed when DMF was used as a solvent. On the other hand, complete retention of the configuration was confirmed when benzene was used :
(3)(Z)-bromoenyne led to (1E,3Z-, (1Z,3E)-, (1E,3Z)-and (1Z,3E)-1-iododiene in several steps stereoselectively.
Stereo controlled synthesis of 13-ethyl and 13-phenyl substituted 11Z-retinal by Suzuki coupling of C1-C10 and C11-C fragments
Trienylboronic acid corresponding to a C1-C10 fragment of 11Z-retinal was prepared from dieneyne through idodotriene. (2E,5Z)-3-Ethyl-5-iodopenta-2,4-dienyl silyl ether and (2Z,5Z)-5-iodo-3-phenylpenta-2,4-dienyl silyl ether were prepared by the above methodology. The two fragments were combined by Suzuki coupling to give 13-ethyl and 13-phenyl substituted 11Z-retinal skeleton under the stereocontrolled manner.
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