Simple and versatile synthesis of branched polyols: (+)-2-C-methylerythritol and (+)-2-C-methylthreitol
摘要:
The paper reports a new approach for the enantioselective synthesis of 2-C-methyl tetrols. The procedure has been utilized for preparing methylthreitol and methylerythritol, a putative intermediate in the mevalonate-independent biosynthesis of terpenoids in bacteria, algae and higher plants. The methodology offers straightforward access to related compounds and isotopically labeled derivatives. (C) 2000 Elsevier Science Ltd. All rights reserved.
Tetrasubstituted Pyrrolidines via a Tandem Aza-Payne/Hydroamination Reaction
摘要:
A facile tandem aza-Payne/hydroamination reaction of aziridinol is reported, which yields highly functionalized pyrrolidines. Addition of alkynyl Grignards to 2,3-aziridinals yields, in most cases, high syn to anti ratios of the aziridinol. Treatment of the syn-aziridinol with base leads initially to an aza-Payne rearrangement, which juxtaposes the amine and the alkyne in favorable orientation to complete the hydroamination. The anti-aziridinol undergoes the aza-Payne rearrangement, but cannot proceed further with the hydroamination.
The construction of a chiral building block with a quaternary carbon center is described, based on the Lewis acid-catalyzedacylmigration of α,β-epoxy ketone with alkyl and alkenyl substituents.
IspG Converts an Epoxide Substrate Analogue to (<i>E</i>)-4-Hydroxy-3-methylbut-2-enyl Diphosphate: Implications for IspG Catalysis in Isoprenoid Biosynthesis
作者:Rodney L. Nyland II、Youli Xiao、Pinghua Liu、Caren L. Freel Meyers
DOI:10.1021/ja907470n
日期:2009.12.16
IspG is an intriguing enzyme in bacteria, parasite, and plant isoprenoid biosynthesis, and its catalytic mechanism remains elusive. We report here the synthesis of (2R,3R)-4-hydroxy-3-methyl-2,3-epoxybutanyl diphosphate (Epoxy-HMBPP), a proposed intermediate in one of the frequently cited mechanistic models. We have also demonstrated that this epoxide analogue is a catalytically competent IspG substrate. This study represents the first mechanistic study of this important enzyme.
Convergent Enantioselective Synthesis of the Tricyclic Core of Phomactin A
作者:Peter J. Mohr、Randall L. Halcomb
DOI:10.1021/ol026159t
日期:2002.7.1
[GRAPHICS]The tricyclic core of phomactin A was synthesized from 6,6-dimethyl-2-cyclohexen-1-one. Key reactions include the addition of a cyclohexenyllithium reagent to an epoxyaldehyde and a regioselective intramolecular epoxide opening to install the oxadecalin core.
Concise Synthesis of (+)-2-<i>C</i>-Methyl-<scp>d</scp>-erythritol-4-phosphate
作者:Angelo Fontana
DOI:10.1021/jo005732o
日期:2001.4.1
Tetrasubstituted Pyrrolidines via a Tandem Aza-Payne/Hydroamination Reaction
作者:Jennifer M. Schomaker、Andrea R. Geiser、Rui Huang、Babak Borhan
DOI:10.1021/ja068077w
日期:2007.4.1
A facile tandem aza-Payne/hydroamination reaction of aziridinol is reported, which yields highly functionalized pyrrolidines. Addition of alkynyl Grignards to 2,3-aziridinals yields, in most cases, high syn to anti ratios of the aziridinol. Treatment of the syn-aziridinol with base leads initially to an aza-Payne rearrangement, which juxtaposes the amine and the alkyne in favorable orientation to complete the hydroamination. The anti-aziridinol undergoes the aza-Payne rearrangement, but cannot proceed further with the hydroamination.