Keio University · 화학
노리타카 치다 교수의 연구실은 유기합성화학 분야에서 특히 자연물의 전합합성과 입체선택적 반응 전략에 중점을 두고 있습니다. N-메톡시아미드를 활용한 카이랄리티 유지 합성, Overman 재배열, 페리에르 재배열 등 고도로 제어된 반응을 통해 복잡한 생체활성 화합물의 합성을 효율적으로 구현합니다. 특히 보호기 최소화와 반응성 기능기의 선택적 반응성을 고려한 철저한 반응 설계가 두드러집니다. 이는 자연물 합성의 정점으로 평가받는 고도의 전략적 접근을 반영합니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
A chemoselective approach for the total synthesis of (±)-gephyrotoxin has been developed. The key to success was the utilization of N-methoxyamides, which enabled the direct coupling of the amide with an aldehyde and selective reductive nucleophilic addition to the amide in the presence of a variety of sensitive and electrophilic functional groups, such as a methyl ester. This chemoselective approach minimized the use of protecting-group manipulations and redox reactions, which resulted in the m
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTotal synthesis of antibiotic hygromycin ANoritaka Chida, Masami Ohtsuka, Keiichi Nakazawa, and Seiichiro OgawaCite this: J. Org. Chem. 1991, 56, 9, 2976–2983Publication Date (Print):April 1, 1991Publication History Published online1 May 2002Published inissue 1 April 1991https://pubs.acs.org/doi/10.1021/jo00009a009https://doi.org/10.1021/jo00009a009research-articleACS PublicationsRequest reuse permissionsArticle Views977Altmetric-Citations81LEARN ABOUT
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTotal synthesis of (+)-lycoricidine and its 2-epimer from D-glucoseNoritaka Chida, Masami Ohtsuka, and Seiichiro OgawaCite this: J. Org. Chem. 1993, 58, 16, 4441–4447Publication Date (Print):July 1, 1993Publication History Published online1 May 2002Published inissue 1 July 1993https://pubs.acs.org/doi/10.1021/jo00068a045https://doi.org/10.1021/jo00068a045research-articleACS PublicationsRequest reuse permissionsArticle Views1075Altmetric-Citations77LEAR
Abstract Conversion of hex-5-enopyranosides into substituted cyclohexanones (Ferrier rearrangement) was found to proceed efficiently with a catalytic amount of various mercury(II) salts at room temperature in a neutral solvent system. Among the mercury(II) salts tested, mercury(II) trifluoroacetate showed the highest activity. Four optically active cyclohexenones were prepared from hex-5-enopyranosides utilizing this method.
The chiral and stereoselective synthesis of (+)-lactacystin 1, the first non-protein neurotrophic factor, is described; the γ-lactam portion possessing a quaternary carbon in 1 was constructed stereoselectively from D-glucose using the allylic trichloroacetimidate rearrangement (Overman rearrangement) as the key reaction.
An iridium-catalyzed reductive nucleophilic addition to secondary amides is reported. After the iridium-catalyzed reduction, the resulting imines can undergo the Strecker reaction, the Mannich reaction, allylation, and [3 + 2]-cycloaddition. The method shows high chemoselectivity in the presence of other functional groups such as methyl ester.
An approach to cyclic nitrones from N-hydroxylactam derivatives is documented. The nucleophilic addition of an organolithium reagent to an N-OSEM [SEM=2-(trimethylsilyl)ethoxymethyl] lactam forms a five-membered chelated intermediate, which undergoes both elimination and deprotection to give a fully substituted nitrone in a one-pot process. When combined with the N-oxidation of easily available chiral lactams, this method becomes especially useful for the quick synthesis of chiral nitrones in en
The total synthesis of the antifungal antibiotic, polyoxin J 1 starting from myo-inositol is described; the two key components, 2 and 3, were prepared from a pair of optically resolved myo-inositol derivatives 4L and 4D, respectively, using a highly regioselective Baeyer–Villiger reaction, and finally coupled to complete the total synthesis.
The chiral and stereoselective synthesis of antimitotic phenanthridone alkaloids, (+)-7-deoxypancratistatin (1) and (+)-7-deoxytrans-dihydronarciclasine (2) is described.Both natural products were synthesized from the common compound (4), which had been prepared from D-glucose and employed for the synthesis of lycoricidine (3).The highly oxygenated phenanthridone alkaloids,l represented by pancratistatin?a7-deoxypancratistatin(1),2b 7-deoxy-trans-dihydronarciclasine (t)?c and lycoricidine (3)2d
A chirality transfer approach using acyclic polyol intermediates for the synthesis of (+)-neostenine (1) has been developed. The sequential Overman/Claisen rearrangement of an allylic 1,2-diol was especially useful, installing two contiguous stereocenters with complete diastereoselectivity in a one-pot sequence. The SmI<sub>2</sub> -mediated cyclization and the subsequent chemoselective reduction of a lactam moiety accomplished the first enantioselective total synthesis of (+)-neostenine (1).
