Asymmetric total synthesis of (−)-mangiferaelactone by using an appropriately substituted thiophene as a masked synthon for C-alkyl glycoside
摘要:
Asymmetric total synthesis of naturally occurring nonenolide (-)-mangiferaelactone was attempted through RCAM (ring closing alkyne metathesis) reaction. As the attempted RCAM reaction failed, the synthesis was finally achieved by successful exploration of a ring closing metathesis (RCM) reaction. 2-Propylthiophene was used as a masked synthon for n-heptyl glycoside, which served as main source for one of the RCM precursors and accessed by reductive desulfurization (Mozingo type reduction) of an appropriately substituted thiophene ribofuranoside. The other RCM precursor was accessed by applying an enzymatic kinetic resolution/Mitsunobu inversion sequence to an alkyne alcohol. (C) 2015 Elsevier Ltd. All rights reserved.
Asymmetric total synthesis of (−)-mangiferaelactone by using an appropriately substituted thiophene as a masked synthon for C-alkyl glycoside
摘要:
Asymmetric total synthesis of naturally occurring nonenolide (-)-mangiferaelactone was attempted through RCAM (ring closing alkyne metathesis) reaction. As the attempted RCAM reaction failed, the synthesis was finally achieved by successful exploration of a ring closing metathesis (RCM) reaction. 2-Propylthiophene was used as a masked synthon for n-heptyl glycoside, which served as main source for one of the RCM precursors and accessed by reductive desulfurization (Mozingo type reduction) of an appropriately substituted thiophene ribofuranoside. The other RCM precursor was accessed by applying an enzymatic kinetic resolution/Mitsunobu inversion sequence to an alkyne alcohol. (C) 2015 Elsevier Ltd. All rights reserved.
Stereoselective Total Synthesis of (+)-Oploxyne A, (−)-Oploxyne B, and Their C-10 Epimers and Structure Revision of Natural Oploxyne B
作者:J. S. Yadav、Kumaraswamy Boyapelly、Sathish Reddy Alugubelli、Srihari Pabbaraja、Janakiram R Vangala、Shasi V Kalivendi
DOI:10.1021/jo102445h
日期:2011.4.15
The first totalsynthesis of recently isolated diacetylene alcohols oploxyne A, oploxyne B, and their C-10 epimers was accomplished. The structure of natural oploxyne B has been revised. The key steps involved are base-induced double elimination of a carbohydrate-derived β-alkoxy chloride to generate the chiral acetylenic alcohol and Cadiot−Chodkiewicz cross-coupling reaction. The target compounds