Synthesis of Macrocyclic Lactones via Ring Transformation of 4-(-Hydroxyalkyl)-1,3-oxazol-5(4H)-ones

被引：3

作者：

Fritschi, Stephan P. ^{[1
,2
]}

Linden, Anthony ^{[1
]}

Heimgartner, Heinz ^{[1
]}

机构：

[1] Univ Zurich, Dept Chem, Winterthurerstr 190, CH-8057 Zurich, Switzerland

[2] Carbogen Amcis AG, Hauptstr 171, CH-4416 Bubendorf, Switzerland

来源：

HELVETICA CHIMICA ACTA | 2016年 / 99卷 / 07期

关键词：

Lactones; 1,3-Oxazol-5(4H)-ones; Ring transformation; Direct amide cyclization; Alkylation; X-Ray crystallography; ALPHA-AMINO-ACIDS; AZIRINE OXAZOLONE METHOD; CYCLIC DEPSIPEPTIDES; CRYSTAL-STRUCTURE; CHEMISTRY; PEPTIDES;

D O I：

10.1002/hlca.201600023

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The synthesis of -benzamido--benzyl lactones 23 of various ring size was achieved either via direct amide cyclization' by treatment of 2-benzamido-2-benzyl--hydroxy-N,N-dimethylalkanamides 21 in toluene at 90 - 110 degrees with HCl gas or by ring transformation' of 4-benzyl-4-(-hydroxyalkyl)-2-phenyl-1,3-oxazol-5(4H)-ones under the same conditions. The precursors were obtained by C-alkylations of 4-benzyl-2-phenyl-1,3-oxazol-5(4H)-one (15) with THP- or TBDMS-protected -hydroxyalkyl iodides. Ring opening of the THP-protected oxazolones by treatment with Me2NH followed by deprotection of the OH group gave the diamides 21, whereas deprotection of the TBDMS series of oxazolones 25 with TBAF followed by treatment with HCl gas led to the corresponding lactones 23 in a one-pot reaction.

引用

页码：523 / 538

页数：16

共 41 条

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