endogenous mediator to resolve inflammation, was synthesized by Wittig reaction between the C15–C20 aldehyde and the C10–C14 phosphonium salt possessing the vinyl iodo moiety followed by Suzuki–Miyaura coupling of the resulting vinyl iodide with the vinyl borane of the C1–C9 part, which was derived from the corresponding acetylene by hydroboration. The C5 and C18 chiral centers in these parts were created
Reaction of 1-Trimethylsilyl-1,2-epoxy-3-alkanols with Alkynes and Application to the Synthesis of 18-HEPE
作者:Yuichi Kobayashi、Yutaro Nanba、Masao Morita
DOI:10.1055/s-0037-1610194
日期:2018.8
(E)-TMS-C≡C-CH=CHCH(OH)R. The (E) stereochemistry was independent of the anti/syn stereochemistry, but the syn isomers showed higher reactivity than the anti isomers. The reaction was applied to the synthesis of (18R)- and (18S)-HEPE.
A new and highly stereocontrolled entry to terminal conjugated trienes is described which relies upon the diastereoselective [2,3]Wittig rearrangement of > (silyl)allylic propargyl ethers followed by Peterson olefination. The synthetic utility of this method is demonstrated by the stereocontrolled synthesis of sarohornene B and C (marine natural products).
Stereoselective ozonolysis of TMS-substituted allylic alcohol derivatives and synthesis of 14<i>R</i>,15<i>S</i>- and 14<i>S</i>,15<i>S</i>-diHETE
作者:Shun Saito、Takashi Yamazaki、Yuichi Kobayashi
DOI:10.1039/c8ob02116c
日期:——
contrast, Z-olefins selectively gave the syn isomers with syn/anti ratios of 4–19 : 1. Facial selection was speculated based on the Cieplak effect. This ozonolysis was successfully applied for the synthesis of 14R,15S- and 14S,15S-diHETEs (anti and syn isomers, respectively) in enantioenriched forms.
TMS取代的烯烃的臭氧分解可产生α-羰基TMS过氧化物,而不会裂解C C键。在此,使用(E)-和(Z)-(1-TMS)alk-1-en-3-ols的甲硅烷基衍生物研究了臭氧分解中的立体化学。(E)异构体经Ph 3 P还原后,提供了主要的立体异构体(抗/ syn = 3–9:1),为抗-3-甲硅烷氧基-2-(TMS-氧基)醛。Z-烯烃选择性生成具有syn / anti的顺式异构体。比例为4:19:1。根据Cieplak效应推测了面部选择。此臭氧分解被成功地应用于14的合成- [R,15小号-和14小号,15小号(-diHETEs抗和顺式在对映体富集形式的分别的异构体,)。
The Regioselectivity of 1,3-Disubstituted Allylmetal Species Towards Electrophiles: 1-(Trimethylsilyl)alk-2-enylpotassium Compounds