Cerium(IV) compound has been utilized extensively for a variety of oxidative transformations. These reactions have been limited to the oxidative coupling reactions. It has been found that silylated pyrimidine bases reacted with 1, 3-dioxolane in the presence of cerium ammonium nitrate to give the corresponding acyclic nucleosides in good yields.
Glycals are the key intermediates in the synthesis of C-nucleosides. Glycals reacted with heterocyclic bases mediated by benzeneselenenyl chloride to give 2'-(selenophenyl)-substituted nucleosides. The introduction of seleno-group and base with high stereoselectivity and regioselectivity was performed in good yield.
During the study on developing functionalization of uracil derivatives at C-5 position of uracils, we have found that uracil reacted with diphenyldiselenide in the presence of manganese(III) acetate in acetic acid to give 5-phenylselenenyl uracil. Formation of a selenium electrophile which is generated by the reaction of manganese(III) acetate with diphenyldiselenide appears to be involved in this reaction.
Nucleosides modified at C-5 position of the pyrimidine base have become important components of synthetic oligonucleosides probes. It has been found that the pyrimidine bases reacted with diethyl malonate in the presence of manganse(III) acetate in acetic acid to afford the pyrimidine bases modified at C-5 by C-C-bond formation. Various pyrimidine bases reacted with diethyl malonate and manganese(III) acetate to give 5-(diethyl acetoxy-methanedicarboxylate) pyrimidines in good yields.
(S)-5-(t-Butyl-diphenylsiloxymethyl)-2-(5H)-furanone reacted with 1,3-dioxolane in the presence of $(n-Bu_4N)_2S_2O_8$ to give the 3'-1,3-dioxolanylated lactone by the antiaddition with high stereoselectivity. The 3'-deoxy-3'-branched chain-substituted sugar derivatives can be used for coupling with silylated base with various Lewis acid. 3'-Masked formylated nucleoside will serve as valuable synthetic intermediates in the preparation of more elaborate nucleoside analogs for potential medicinal applications. While uridines reacted with 1,3-dioxolane in the presence of $(n-Bu_4N)_2S_2O_8$ to give C-6-masked formylated-5,6-dihydrouridines, which is a precursor of C-6 formyl uridines. This methodology provides the diverse functionalizations at C-6 of pyrimidine nucleosides.
세륨(IV)유도체는 산화변환 반응에 광범위하게 이용되고 있지만 산화결합 반응에는 많이 사용되지 않았다. 본연구에서는 세륨암모니움나이트레이트를 이용하여 1,3-디옥솔란으로 부터 한반응용기에서 비고리 핵산유도체를 좋은 수율로 합성할수 있었다. 글리칼은 C-핵산합성에서 중요한 중간체이다. 글리칼과 셀레니움 화합물을 이용하여 당의 2번위치에 셀레니움이 치환된 2-디옥시핵산을 입체 선택적으로 합성하였다. 우라실의 5번위치에 셀레니움치환체를 도입하는 방법으로서 디세레나이드와 망간(III) 아세테이트를 사용하는 반응시스템을 개발하였다. 피리미딘 핵산의 5번위치에 새로운 관능기를 도입하는것은 올리고핵산의 연구에서 매우 중요한 위치를 차지하고 있다. 피리미딘핵산과 디에틸말로내이틀 망간(III) 아세테이트 존재하에서 반응시켜 피리미딘핵산의 5번위치에 새로운 탄소 결합을 생성하는 방법을 발견하였다. 5번 위치에 입체적으로 큰 치환기가 도입된 퓨라논을 출발물질로하여 1,3-디옥솔란과 술페이트라디칼 반응을 이용하여 당의 3번위치에 탄소고리가 하나 늘어난 핵산을 합성하였다. 그리고 1,3-디옥솔란과 술페이트라디칼 반응을 이용하여 피리미딘핵산 6번위치에 보호된 포밀기가 도입된 5,6-디하이드로 피리미딘핵산을 합성하였다.
