{"title":"通过串联维蒂希反应和迈克尔反应从吡喃糖合成 2-(C-糖基)乙酸酯的流程化学","authors":"Jack J. Bennett, and , Paul V. Murphy*, ","doi":"10.1021/acs.oprd.3c00414","DOIUrl":null,"url":null,"abstract":"<p >C-Glycosyl compounds (C-glycosides) are a class of saccharide derivatives with improved stability over their O-linked counterparts. This paper reports the synthesis of several <i>trans</i>-2-(C-glycosyl)acetates via a tandem Wittig–Michael reaction from pyranoses (cyclic hemiacetals) using continuous flow processing, which gave improvements compared to reactions conducted in round-bottom flasks. Products were isolated in yields of >60% from reactions of benzyl-protected xylopyranoses, glucopyranoses, and galactopyranoses at higher temperatures and pressures, which were superior to yields from batch procedures. A two-step procedure involving the Wittig reaction followed by Michael reaction (intramolecular oxa-Michael) of the unsaturated ester obtained in the presence of DBU was developed. Reactions of protected mannopyranose gave low yields in corresponding reactions in flow due to competing C-2 epimerization.</p>","PeriodicalId":55,"journal":{"name":"Organic Process Research & Development","volume":"28 5","pages":"1848–1859"},"PeriodicalIF":3.5000,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acs.oprd.3c00414","citationCount":"0","resultStr":"{\"title\":\"Flow Chemistry for Synthesis of 2-(C-Glycosyl)acetates from Pyranoses via Tandem Wittig and Michael Reactions\",\"authors\":\"Jack J. Bennett, and , Paul V. Murphy*, \",\"doi\":\"10.1021/acs.oprd.3c00414\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p >C-Glycosyl compounds (C-glycosides) are a class of saccharide derivatives with improved stability over their O-linked counterparts. This paper reports the synthesis of several <i>trans</i>-2-(C-glycosyl)acetates via a tandem Wittig–Michael reaction from pyranoses (cyclic hemiacetals) using continuous flow processing, which gave improvements compared to reactions conducted in round-bottom flasks. Products were isolated in yields of >60% from reactions of benzyl-protected xylopyranoses, glucopyranoses, and galactopyranoses at higher temperatures and pressures, which were superior to yields from batch procedures. A two-step procedure involving the Wittig reaction followed by Michael reaction (intramolecular oxa-Michael) of the unsaturated ester obtained in the presence of DBU was developed. Reactions of protected mannopyranose gave low yields in corresponding reactions in flow due to competing C-2 epimerization.</p>\",\"PeriodicalId\":55,\"journal\":{\"name\":\"Organic Process Research & Development\",\"volume\":\"28 5\",\"pages\":\"1848–1859\"},\"PeriodicalIF\":3.5000,\"publicationDate\":\"2024-02-28\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://pubs.acs.org/doi/epdf/10.1021/acs.oprd.3c00414\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Organic Process Research & Development\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://pubs.acs.org/doi/10.1021/acs.oprd.3c00414\",\"RegionNum\":3,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, APPLIED\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Organic Process Research & Development","FirstCategoryId":"92","ListUrlMain":"https://pubs.acs.org/doi/10.1021/acs.oprd.3c00414","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, APPLIED","Score":null,"Total":0}
Flow Chemistry for Synthesis of 2-(C-Glycosyl)acetates from Pyranoses via Tandem Wittig and Michael Reactions
C-Glycosyl compounds (C-glycosides) are a class of saccharide derivatives with improved stability over their O-linked counterparts. This paper reports the synthesis of several trans-2-(C-glycosyl)acetates via a tandem Wittig–Michael reaction from pyranoses (cyclic hemiacetals) using continuous flow processing, which gave improvements compared to reactions conducted in round-bottom flasks. Products were isolated in yields of >60% from reactions of benzyl-protected xylopyranoses, glucopyranoses, and galactopyranoses at higher temperatures and pressures, which were superior to yields from batch procedures. A two-step procedure involving the Wittig reaction followed by Michael reaction (intramolecular oxa-Michael) of the unsaturated ester obtained in the presence of DBU was developed. Reactions of protected mannopyranose gave low yields in corresponding reactions in flow due to competing C-2 epimerization.
期刊介绍：
The journal Organic Process Research & Development serves as a communication tool between industrial chemists and chemists working in universities and research institutes. As such, it reports original work from the broad field of industrial process chemistry but also presents academic results that are relevant, or potentially relevant, to industrial applications. Process chemistry is the science that enables the safe, environmentally benign and ultimately economical manufacturing of organic compounds that are required in larger amounts to help address the needs of society. Consequently, the Journal encompasses every aspect of organic chemistry, including all aspects of catalysis, synthetic methodology development and synthetic strategy exploration, but also includes aspects from analytical and solid-state chemistry and chemical engineering, such as work-up tools，process safety, or flow-chemistry. The goal of development and optimization of chemical reactions and processes is their transfer to a larger scale; original work describing such studies and the actual implementation on scale is highly relevant to the journal. However, studies on new developments from either industry, research institutes or academia that have not yet been demonstrated on scale, but where an industrial utility can be expected and where the study has addressed important prerequisites for a scale-up and has given confidence into the reliability and practicality of the chemistry, also serve the mission of OPR&D as a communication tool between the different contributors to the field.
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