Water-catalyzed racemisation of lactide

	Water-catalyzed racemisation of lactide
	Feng LD ; Chen XS ; Sun B ; Bian XC ; Chen ZM
刊名	polymer degradation and stability
	2011
卷号	96 期号:10 页码:1745-1750
关键词	HIGH-MOLECULAR-WEIGHT L RING-OPENING POLYMERIZATION L-LACTIDE POLY(LACTIC ACID) THERMAL-DEGRADATION POLY(L-LACTIDE) POLYLACTONES POLYESTERS ALKOXIDES BEHAVIOR
ISSN号	0141-3910
通讯作者	chen xs
中文摘要	the reactions of lactide racemisation, hydrolysis, or alcoholysis in the presence of water or anhydrous alcohol have been investigated separately. a small amount of water leads to lactide racemisation, hydrolysis, or both. water acts as a catalyst for the racemisation of lactide. the racemisation mechanism has been studied by substituting d(2)o instead of h(2)o and measuring the substituent by gas chromatography-mass spectrometry (gc-ms). the experimental results show that the hydrogen atom on a chiral carbon of lactide is substituted by a (2)h atom of d(2)o. the reaction of lactide with water is in good agreement with the mechanism of addition-elimination. the addition of water to the carbonyl group produces an intermediate with a pair of hydroxyls connected to a carbon atom. if a hydroxyl hydrogen atom is transferred to the ester bond (co-o), the hydrolysis of lactide generally occurs. any of these hydroxyls could also be dehydrated with the close methine, thus producing an enolate, and the transfer of hydrogen from the enolic hydroxyl group results in lactide racemisation. the conversion of d- or l-lactide into meso-lactide is a reversible and endothermic reaction when catalyzed by water. when lactide reacts with alcohol, its alcoholysis occurs more readily than its racemisation. (c) 2011 elsevier ltd. all rights reserved.
收录类别	SCI收录期刊论文
语种	英语
WOS记录号	WOS:000295501000006
公开日期	2012-06-08
内容类型	期刊论文
源URL	[http://ir.ciac.jl.cn/handle/322003/44319]
专题	长春应用化学研究所_长春应用化学研究所知识产出_期刊论文
推荐引用方式 GB/T 7714	Feng LD,Chen XS,Sun B,et al. Water-catalyzed racemisation of lactide[J]. polymer degradation and stability,2011,96(10):1745-1750.
APA	Feng LD,Chen XS,Sun B,Bian XC,&Chen ZM.(2011).Water-catalyzed racemisation of lactide.polymer degradation and stability,96(10),1745-1750.
MLA	Feng LD,et al."Water-catalyzed racemisation of lactide".polymer degradation and stability 96.10(2011):1745-1750.