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Development of Allyl-Transfer Reaction and Its New Aspect

烯丙基转移反应的进展及其新局面

基本信息

批准号：
15350063
负责人：
NOKAMI Junzo
金额：
$ 8.26万
依托单位：
Okayama University of Science
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

To date, there have been no reported methods for effectively synthesizing homoallylic alcohols (2,RCH(OH)CH_2CH=CHR^3) via alk-2-enylation of aldehydes (RCHO). On the other hand, we recently discovered the first convenient and highly stereoselective but-2-enylation of aldehydes (RCHO) to give (RC^*H(OH)CH_2CH=CHCH_3) by allyl-transfer reaction, in which γ-adduct of homoallylic alcohol (1,R^1R^2C^*(OH)C^*HR^3CH=CH_2) surved as an allyl donor and its allylic functionality (R^3CH=CHCH_2) was transfered to aldehyde due to [3.3]-sigmatropic rearrangement via the most stable 6-membered chair-like cyclic transition state of the oxocarbenium ion intermediate (RCH=O^+C^*R^1R^2C^*HR^3CH=CH_2; R^3=CH_3) derived from hemiacetal (RCH(OH)OC^*R^1R^2C^*HR^3CH=CH^2) of aldehyde and 1. Further, we demontrated the possibility of alk-2-enylation of aldehydes via an allyl-transfer reaction using optically active menthones ((-)-,(+)-, and (+)-iso) as chiral auxiliaries. We also discovered that this improved the yield of the product due to an icrease in the steric valk of the alkyl chains. Highly optically acitive 2,3,4,6-tetrasubstituted tetrahydropyrans were prepared in good yield by Prins cyclization reaction of 2 and aldehydes.More recently, we discovered an asymmetric 4-benzyloxybut-2-enylation of aldehydes to give α-adduct of homoallylic alcohols (RC^*H(OH)CH_2CH=CHCH_2OBn), in which we successfully prepared the necessary homoallylic alcohol (R^4C^*H(HO)C^*HR^3CH=CH^2; R^3=CH_2OBn) without using organometallic compounds such as R^3CH=CHCH_2M (M=metal) which is impossible to prepare because of its intability (when R^3=CYR_2;Y=OBn, halogens).We discovered "Allyl-Transfer reaction" which gave highly optically active and a variety of fuctionalyzed α-adduct of homoallylic alcohols, conveniently.

迄今为止，还没有报道过通过烷基-2-烯化醛（RCHO）有效合成同丙烯醇（2，RCH(OH)CH_2CH=CHR^3）的方法。另一方面，我们最近发现了通过烯丙基转移反应生成（RC^*H(OH)CH_2CH=CHCH_3）的第一个方便且具有高度立体选择性的乙基化醛（RCHO）。其中，均烯丙醇的γ-加合物（1,R^1R^2C^*(OH)C^*HR^3CH=CH_2）作为烯丙基供体存在，其烯丙基官能团（R^3CH=CHCH_2）通过氧羰基中间体（RCH=O^+C^*R^1R^2C^*HR^3CH=CH_2; R^3=CH_3）的最稳定的六元椅状环过渡态（RCH(OH)OC^*R^1R^2C^*HR^3CH=CH^2）的[3.3]-异位重排转移到醛上。此外，我们还证明了使用光学活性薄荷酮((-)-、（+)-和(+)-iso）作为手性助剂，通过烯丙基转移反应实现醛类烷烃-2-烯化的可能性。我们还发现，由于烷基链的空间间距增加，这提高了产品的收率。通过2与醛的普林斯环化反应，制备了具有高旋光性的2,3,4,6-四取代四氢吡喃。最近，我们发现了一个不对称的4-苯氧基丁-2-烯基化反应，得到了α-烯丙基醇的加成物（RC^*H(OH)CH_2CH=CHCH_2OBn），我们成功地制备了所需的均烯丙基醇(R^4C^*H(HO)C^*HR^3CH=CH^2；R^3=CH_2OBn)，而不使用有机金属化合物，如R^3CH=CHCH_2M （M=金属），这是不可能制备的，因为它的不稳定性（当R^3=CYR_2；Y=OBn，卤素）。我们发现了“烯丙基转移反应”，方便地得到了高旋光性和多种功能化的α-加合物。