| Budget Amount *help |
¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000)
Fiscal Year 2010: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2009: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2008: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
|
|---|
| Research Abstract |
1) We developed a stereoselective synthesis of cyclopropane derivatives utilizing a highly stereoselective SMI_2-promoted Reformatsky-type reaction and acylation of 1-chlorocyclopropanecarboxylic esters. The present method is a new avenue for the stereoselective synthesis of highly substituted cyclopropylcarbonyl compounds. Utilizing radical formylation and the present protocols, we achieved a highly stereoselective double-carbon elongation on the dichloro- carbon of gem-dichlorocyclopropanes. We also developed a stereoselective synthesis of cyclopropane derivatives utilizing a highly stereoselective SmI_2-promoted C-silylation and alkylation of 1-chlorocyclopropane- carboxylic esters. Based on the fact that no O-TMS-product was obatained, a SmI_2-O-enolate might not be generated or should exist as a particular intermediate that can not react with TMSCl on oxygen atom. 2) We developed a novel synthesis of 1-aryl-1,2-dihydronaphthalene-3-carboxylic acid esters utilizing a Lewis acid-mediated regioselective ring-expansion of methyl (aryl-hydroxymethyl)cyclopropanecarboxylate. Application of the present method to a total synthesis of natural product is now being performed. 3) We achieved the first total synthesis of a novel (±)-6'-methoxyretrojusticidin B, which was proposed as procumphthalide A, utilizing regiocontrolled benzannulation of an aryl(aryl')-2,2-dichlorocyclopropylmethanol as the key step. 1H-NMR spectral data suggested that the structure of the synthesized product, 6'-methoxyretrojusticidin B, was inconsistent with that of natural procumphthalide A. The revised structural elucidation of natural procumphthalide A was concluded to be 5'-methoxyretrochinensin.
|
