Improved synthesis of substituted 2,6-dioxabicyclo[3.1.1]heptanes: 1,3-anhydro-2,4,6-tri-O-benzyl- and 1,3-anhydro-2,4,6-tri-O-p-bromobenzyl-β-d-mannopyranose
A Simple Synthesis of Methyl 2,3,6- and 2,4,6-Tri-<i>O</i>-benzyl-α-D-mannosides
作者:Shinkiti Koto、Kazuhiro Takenaka、Naohiko Morishima、Akiko Sugimoto、Shonosuke Zen
DOI:10.1246/bcsj.57.3603
日期:1984.12
Cotrolled benzylation of methyl α-D-mannopyranoside with benzyl chloride and LiOH selectively gave the 2,3,6-tribenzyl ether in a 53% yield. Such a reaction using benzyl chloride and KOH afforded mainly the 2,4,6-tribenzyl ether in a 41% yield. The products were allylated and then hydrolyzed to give the corresponding 1-OH derivatives.
Ceric ammonium nitrate/acetic anhydride: A tunable system for the <i>O</i>-acetylation and mononitration of diversely protected carbohydrates
作者:Mohindra Seepersaud、Savita Seecharan、Lorale J. Lalgee、Nigel Kevin Jalsa
DOI:10.1080/00397911.2016.1230219
日期:2017.5.3
ABSTRACT Esterification of a wide range of partially protected carbohydrate derivatives was achieved using acetic anhydride and a catalytic amount of cericammoniumnitrate (CAN). Compatibility with the commonly used protecting groups was demonstrated, with the esterified products being furnished in good yields. Apart from affording the O-acetylated products, their mononitrated counterparts were also
摘要 使用乙酸酐和催化量的硝酸铈铵 (CAN) 实现了多种部分保护的碳水化合物衍生物的酯化。证明了与常用保护基团的相容性,酯化产物以良好的产率提供。除了提供 O-乙酰化产物外,还产生了它们的单硝化对应物,这取决于起始材料的反应性。降低 CAN 的摩尔当量只能提供 O-乙酰化产物,而增加它有利于单硝化衍生物。图形概要