Synthesis and Analysis of the All-(S) Side Chain of Phosphomycoketides: A Test of NMR Predictions for Saturated Oligoisoprenoid Stereoisomers

Jeffrey Buter; Edmund Yeh; Owen Budavich; Krishnan Damodaran; Adriaan Minnaard; Dennis Curran

Synthesis and Analysis of the All-(S) Side Chain of Phosphomycoketides: A Test of NMR Predictions for Saturated Oligoisoprenoid Stereoisomers

Jeffrey Buter, Edmund Yeh, Owen Budavich, Krishnan Damodaran, Adriaan Minnaard, Dennis Curran

Research output: Contribution to journal › Article › Academic › peer-review

Abstract

(4S,8S,12S,16S,20S)-Pentamethylheptacosan-1-ol has been synthesized and analyzed by resolution-enhanced NMR spectroscopy with the aid of a recent set predicted spectra of all its stereoisomers. The configuration was confirmed, but isomer purity of the sample (∼70%) was lower than expected. A truncated analogue, (2S,6S,10S,14S)-2,6,10,14-tetramethylhenicosan-1-ol TBDPS ether, was prepared from a late stage synthetic intermediate. Analysis of its spectra confirmed the configuration and showed that the sample was isomerically pure. The results suggest that a late-stage epimerization, not a failure of an asymmetric synthesis step, caused the formation of minor stereoisomers in the sample of pentamethylheptacosan-1-ol. The study shows the value of the predicted set of oligoisoprenoid spectra and further extends the predictive model to a new subclass of compounds.

Original language	English
Pages (from-to)	4913-4918
Journal	The Journal of Organic Chemistry
Volume	78
Issue number	10
Publication status	Published - 12 Apr 2013
Externally published	Yes

Keywords

organic chemistry
NMR analysis

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https://doi.org/10.1021/jo4005298

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title = "Synthesis and Analysis of the All-(S) Side Chain of Phosphomycoketides: A Test of NMR Predictions for Saturated Oligoisoprenoid Stereoisomers",

abstract = "(4S,8S,12S,16S,20S)-Pentamethylheptacosan-1-ol has been synthesized and analyzed by resolution-enhanced NMR spectroscopy with the aid of a recent set predicted spectra of all its stereoisomers. The configuration was confirmed, but isomer purity of the sample (∼70%) was lower than expected. A truncated analogue, (2S,6S,10S,14S)-2,6,10,14-tetramethylhenicosan-1-ol TBDPS ether, was prepared from a late stage synthetic intermediate. Analysis of its spectra confirmed the configuration and showed that the sample was isomerically pure. The results suggest that a late-stage epimerization, not a failure of an asymmetric synthesis step, caused the formation of minor stereoisomers in the sample of pentamethylheptacosan-1-ol. The study shows the value of the predicted set of oligoisoprenoid spectra and further extends the predictive model to a new subclass of compounds.",

keywords = "organische chemie, NMR-analyse, organic chemistry, NMR analysis",

author = "Jeffrey Buter and Edmund Yeh and Owen Budavich and Krishnan Damodaran and Adriaan Minnaard and Dennis Curran",

year = "2013",

month = apr,

day = "12",

language = "English",

volume = "78",

pages = "4913--4918",

journal = "The Journal of Organic Chemistry",

issn = "0022-3263",

publisher = "American Chemical Society",

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TY - JOUR

T1 - Synthesis and Analysis of the All-(S) Side Chain of Phosphomycoketides

T2 - A Test of NMR Predictions for Saturated Oligoisoprenoid Stereoisomers

AU - Buter, Jeffrey

AU - Yeh, Edmund

AU - Budavich, Owen

AU - Damodaran, Krishnan

AU - Minnaard, Adriaan

AU - Curran, Dennis

PY - 2013/4/12

Y1 - 2013/4/12

N2 - (4S,8S,12S,16S,20S)-Pentamethylheptacosan-1-ol has been synthesized and analyzed by resolution-enhanced NMR spectroscopy with the aid of a recent set predicted spectra of all its stereoisomers. The configuration was confirmed, but isomer purity of the sample (∼70%) was lower than expected. A truncated analogue, (2S,6S,10S,14S)-2,6,10,14-tetramethylhenicosan-1-ol TBDPS ether, was prepared from a late stage synthetic intermediate. Analysis of its spectra confirmed the configuration and showed that the sample was isomerically pure. The results suggest that a late-stage epimerization, not a failure of an asymmetric synthesis step, caused the formation of minor stereoisomers in the sample of pentamethylheptacosan-1-ol. The study shows the value of the predicted set of oligoisoprenoid spectra and further extends the predictive model to a new subclass of compounds.

AB - (4S,8S,12S,16S,20S)-Pentamethylheptacosan-1-ol has been synthesized and analyzed by resolution-enhanced NMR spectroscopy with the aid of a recent set predicted spectra of all its stereoisomers. The configuration was confirmed, but isomer purity of the sample (∼70%) was lower than expected. A truncated analogue, (2S,6S,10S,14S)-2,6,10,14-tetramethylhenicosan-1-ol TBDPS ether, was prepared from a late stage synthetic intermediate. Analysis of its spectra confirmed the configuration and showed that the sample was isomerically pure. The results suggest that a late-stage epimerization, not a failure of an asymmetric synthesis step, caused the formation of minor stereoisomers in the sample of pentamethylheptacosan-1-ol. The study shows the value of the predicted set of oligoisoprenoid spectra and further extends the predictive model to a new subclass of compounds.

KW - organische chemie

KW - NMR-analyse

KW - organic chemistry

KW - NMR analysis

M3 - Article

SN - 0022-3263

VL - 78

SP - 4913

EP - 4918

JO - The Journal of Organic Chemistry

JF - The Journal of Organic Chemistry

IS - 10

ER -

Synthesis and Analysis of the All-(S) Side Chain of Phosphomycoketides: A Test of NMR Predictions for Saturated Oligoisoprenoid Stereoisomers

Abstract

Keywords

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