Stereoselective synthesis of substituted dienes by the double ortho ester Claisen rearrangement
作者:Suk-pyo Hong、Sung-jun Yoon、Byung-chan Yu
DOI:10.1016/j.tetlet.2004.12.015
日期:2005.1
This letter shows the highly stereoselective synthesis of substituted (E)-1,3-dienes from substituted propargylic diols via the double ortho ester Claisenrearrangement. The cyclohexyl-substituted diene undergoes thermal Diels–Alder cycloaddition with maleic anhydride to produce the corresponding bicyclic diester in highly stereoselective manner.
The substitution reactions of diphenyl sec‐alkyl phosphates with Ar2CH anions were swift and proceeded with inversion. In contrast, the diphenyl substituted‐cyclohexyl phosphates proceeded with inversion, but showed different reactivity depending on the relative stereochemistry of the substituent and the (PhO)2PO2 leaving group. The difference in reactivity was rationalized by computational calculation
磷酸二苯基仲烷基磷酸酯与Ar 2 CH阴离子的取代反应迅速进行,并进行了转化。相比之下,二苯基取代的环己基磷酸酯进行了转化,但根据取代基和(PhO)2 PO 2离开基团的相对立体化学,显示出不同的反应性。反应性的差异通过过渡能的计算得到合理化。
Synthesis and in vitro evaluation of ( R ), ( S ) and ( R / S )-2-hexyne-1,4-diol, a natural product produced by fungus Clitocybe catinus , and related analogs as potential anticancer agents
作者:Iza Mirela R.G. Princival、Jeiely G. Ferreira、Teresinha G. Silva、Jaciana S. Aguiar、Jefferson L. Princival
DOI:10.1016/j.bmcl.2016.04.060
日期:2016.6
for natural products and related analogs as potential anticancer agents has seen a significant growth worldwide. Since small sized propargylic diols can be found in nature and chemically synthesized, their evaluation against cancer cells has been of great interest, being a topic of relevance to be investigated. For this purpose, a scalable approach aiming at the synthesis of several propargylic diols
Enzymatic kinetic resolution of internal propargylic diols. Part I: a new approach for the synthesis of (S)-pent-2-yn-1,4-diol, a natural product from Clitocybe catinus
作者:Jeiely G. Ferreira、Cleverson R. Princival、Dyego M. Oliveira、Renata X. Nascimento、Jefferson L. Princival
DOI:10.1039/c5ob00386e
日期:——
Employing a two round sequence EKR, mono- and bis-acetoxy propargylic products were obtained in a high enantiomeric ratio (E > 200). The efficiently resolved chiral 8b was applied in a concise synthesis of (S)-1b, an optically active natural product produced by fungi Clitocybe catinus.
CeCl3-mediated addition of acetylenic bis-lithium salts to aldehydes and ketones: An efficient route to bis-substituted alkyne diols
作者:Jefferson Luiz Princival、Jeiely Gomes Ferreira
DOI:10.1016/j.tetlet.2017.07.094
日期:2017.9
An efficient, chemoselective protocol to access propargylic diols via a CeCl3-mediated addition reaction is reported. Propargylic alcohols were transformed into the corresponding acetylenic bis-lithium salt intermediates, which react with aldehydes and ketones in the presence of dry CeCl3 to furnish the corresponding bis-substituted alkyne diols. This protocol does not involve protection-deprotection