A Concise and Efficient Synthesis of (−)-Allosamizoline
作者:Timothy J. Donohoe、Carla P. Rosa
DOI:10.1021/ol702449m
日期:2007.12.1
A regio- and stereocontrolled total synthesis of (-)-allosamizoline is described. The key steps for this synthesis are ring-closing metathesis to form the cyclopentene core, halocyclization to afford the oxazoline ring, and finally stereoselective alkene radical addition followed by an alkene isomerization reaction to install the hydroxymethyl group. (-)-Allosamizoline was prepared in a total of 13
lost during the cyclopentaneringformation of 1. In the feeding experiments with (6R)- and (6S)-[6-(2)H(1)]-D-glucose, the (6R)-deuterium of glucose was incorporated into the proS position on C-6 of 1, but the (6S)-deuterium of glucose was not incorporated into 1. These results suggested that an intermediate with a 6-aldehyde group is involved in the biosynthesis of the cyclopentanering moiety of 1 and
The structures of allosamidin (1) and methylallosamidin (2), novel insect chitinase inhibitors, were elucidated as 1 and 2 by acid hydrolysis experiments and analyses of 2D-NMR spectra. They are unique basic pseudotrisaccharides consisting of 2-acetamido-2-deoxy-D-allose (N-acetyl-D-allosamine) and a novel aminocyclitol derivative (3), termed allosamizoline.
Preparation of 3,6-di-O-benzylallosamizoline, the aglycon required for the total synthesis of allosamidin and its related compounds, from natural allosamizoline obtained from natural allosamidin is described.
Chemo-enzymatic synthesis of tetra-N-acetyl-chitotetraosyl allosamizoline
作者:Gang-Liang Huang、Xin-Ya Mei、Hou-Cheng Zhang、Peng-George Wang
DOI:10.1016/j.bmcl.2006.03.016
日期:2006.6
A new compound 7, possessing a tetra-N-acetyl-chitotetraosyl moiety as a constituent, was synthesized by bacterial fermentation which used allosamizoline 6 as the initial acceptor. (c) 2006 Elsevier Ltd. All rights reserved.