Lepadiformine A、B 和 C 是使用还原环化策略以对映体纯形式合成的。N -Boc α-氨基腈被去质子化并用对映体纯二溴化物烷基化以提供第一个环。操纵产物以引入磷酸盐离去基团,随后的还原锂化和分子内烷基化形成具有高立体选择性的第二个环。第三个环是通过去保护的胺分子内置换甲磺酸盐形成的。Lepadiformine A 和 B 含有一个与胺相邻的羟甲基。使用 Polonovski-Potier 反应作为关键步骤,按顺序引入该附属物。合成策略具有立体选择性和收敛性,并证明了N的效用-Boc α-氨基腈作为生物碱合成的关键。
A fine addition! A highlyenantioselective and efficient procedure for the amino‐alcohol–zinc‐catalyzedaddition of trimethylsilylacetylene to aromatic, α,β‐unsaturated, and aliphatic aldehydes has been developed (see scheme; R=aryl, alkynyl, or alkyl; TMS=trimethylsilyl; TBDMS=tert‐butyldimethylsilyl). The present protocol was successfully applied in the concise synthesis of the natural products marine
很好的补充!已开发出一种高度对映选择性和高效的程序,用于氨基醇锌催化的三甲基甲硅烷基乙炔加成到芳族,α,β-不饱和和脂肪族醛中(见方案; R =芳基,炔基或烷基; TMS =三甲基甲硅烷基; TBDMS =叔丁基二甲基甲硅烷基)。本协议已成功地应用于天然产物海洋炔醇和法卡林二醇的简明合成中。
A General Asymmetric Synthesis of (R)-Matsutakeol and Flavored Analogs
作者:Jia Liu、Honglian Li、Chao Zheng、Shichao Lu、Xianru Guo、Xinming Yin、Risong Na、Bin Yu、Min Wang
DOI:10.3390/molecules22030364
日期:——
and practical syntheticroute toward chiral matsutakeol and analogs was developed by asymmetric addition of terminal alkyne to aldehydes. (R)-matsutakeol and other flavored substances were feasibly synthesized from various alkylaldehydes in high yield (up to 49.5%, in three steps) and excellent enantiomeric excess (up to >99%). The protocols may serve as an alternative asymmetric synthetic method for
Allyl-aryl coupling between allylic acetates and arylboronicacids took place in the presence of catalytic amounts of Pd(OAc)(2), 1,10-phenanthroline, and AgSbF(6) with high gamma-selectivity and E/Z-selectivity. The reaction of an optically active allylic acetates with an alpha-stereogenic center proceeded with excellent alpha-to-gamma chirality transfer with syn-selectivity and gave the corresponding
An asymmetric formal synthesis of fasicularin (1) is described. This natural product, isolated from the extracts of the marine invertebrate Nephteis fasicularis, has shown modest cytotoxicity towards Vero cells. Fasicularin is among only two members of the cylindricinefamily of natural products, along with lepadiformine (2), to possess a trans A-B ring junction. Key steps of this approach to 1 involve
Our synthetic approach toward fasicularin is presented. Key steps in this construction are a siloxy-epoxide semipinacol rearrangement, a B-alkyl Suzuki reaction and an intramolecular S(N)2 reaction.