Synthesis of Ethers via Reaction of Carbanions and Monoperoxyacetals
作者:ShivaKumar Kyasa、Rebecca N. Meier、Ruth A. Pardini、Tristan K. Truttmann、Keith T. Kuwata、Patrick H. Dussault
DOI:10.1021/acs.joc.5b02043
日期:2015.12.18
organolithium and organomagnesium reagents to furnish moderate to high yields of ethers. The method is successfully applied to the synthesis of alkyl, alkenyl, aryl, heteroaryl, and cyclopropyl ethers, mixed O,O-acetals, and S,S,O-orthoesters. In contrast to reactions of dialkyl and alkyl/silyl peroxides, the displacements of monoperoxyacetals provide no evidence for alkoxy radical intermediates. At the
尽管亲电烷氧基(“ RO +”)从有机过氧化物转移至有机金属化合物为传统的醚化方法提供了补充,但其应用受到与过氧化物反应性和稳定性相关的限制。现在我们证明容易制备的四氢吡喃基单过氧缩醛与sp 3和sp 2有机锂和有机镁试剂反应,以提供中等至高产率的醚。该方法已成功应用于烷基,烯基,芳基,杂芳基和环丙基醚,混合的O,O-乙缩醛和S,S,O的合成-原酸酯。与二烷基和烷基/甲硅烷基过氧化物的反应相反,单过氧缩醛的取代没有提供烷氧基自由基中间体的证据。同时,对于伯,仲或叔醇盐的转移,观察到的高产率,后者涉及对新戊基氧的攻击,与S N 2机制不一致。理论研究表明,涉及路易斯酸的机理促进了有机金属插入O-O键中。
Diastereoselective total synthesis of (+)-morusimic acid B, an amino acid from Morus alba
作者:Marc E. Bouillon、Hartmut H. Meyer
DOI:10.1016/j.tet.2007.01.008
日期:2007.3
An efficient, flexible and diastereoselectivesynthesis of the naturally occurring pyrrolidine amino acid, (+)-morusimic acid B, has been accomplished. Starting from chiral, optically active (+)-(3S)-hydroxy butyric acid methyl ester the key steps of our synthesis are diastereoselective α-alkylation of its dianion to introduce the main part of the side chain, Curtius rearrangement of the hydrazide
A new methodology for the synthesis of β-amino acids
作者:Mukund P. Sibi、Prasad K. Deshpande
DOI:10.1039/a908747h
日期:——
A differentially functionalized succinic acid unit 6 undergoes alkylation with excellent regio- and high stereocontrol at the carbon α to the imide to furnish the alkylated product 7 in 60â83% yield. Selective removal of the imide provides 8 in 80â90% yields. Curtius rearrangement of 8 with retention of stereochemistry provides N-protected β-amino acids (9) in 70â83% yields. Alternatively, selective deprotection of the ester group followed by Curtius rearrangement provides isomeric β-amino acids 14a, 14b, and 14e in good yields. The methodology has been successfully applied to the synthesis of N-Boc-iturinic acid and 2-methyl-3-aminopropanoic acid, components of the antifungal peptide iturin and the cytotoxic depsipeptide cryptophycin respectively.
Construction of Chemical Libraries of Volatile Compounds by Combinatorial Synthesis of Homologous Mixtures: Alk‐4‐en‐1‐ols, Alk‐4‐enals and Methyl Alk‐4‐enoates
作者:Coline Perrin、Nicolas Baldovini
DOI:10.1002/cbdv.202200817
日期:2023.2
for their identification in GC/MS analyses. We demonstrate here that compound libraries can be prepared by combinatorial syntheses using long linear synthetic sequences, i. e., eight step in the case of 4-enals. The resulting mixtures of homologues are still perfectly exploitable to deliver the requested information such as clean mass spectra and good gaschromatographicretentionindices.
包含 66 个线性化合物的化合物库,六个分子家族的 11 个代表:( E )- 和 ( Z )-alk-4-en-1-ols、alk-4-enals 和甲基 alk-4-enoates 的异构体, 是通过组合合成制备的, 以允许创建直接可用于在 GC/MS 分析中识别它们的质谱数据库。我们在这里证明化合物库可以通过使用长线性合成序列的组合合成来制备,即。即,在 4-enals 的情况下为八步。由此产生的同系物混合物仍然可以完美地用于提供所需的信息,例如干净的质谱和良好的气相色谱保留指数。