Mild and efficient tetrahydropyranylation of alcohols-catalysis by lithium perchlorate in diethyl ether
TL;DR: In this article, the tetrahydropyranyl ethers were obtained in the presence of 5 M lithium perchlorate in diethyl ether (5 M LPDE), which is essentially a neutral medium.
About: This article is published in Tetrahedron Letters.The article was published on 1998-12-10. It has received 50 citations till now. The article focuses on the topics: Lithium perchlorate & Diethyl ether.
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15 Apr 2007
TL;DR: In this paper, the authors discuss the properties, production, and industrial uses of furfural and compounds derived from furoic acid on a commercial basis, and the most important specialty chemicals derived from furfurlamine and furfuryl alcohol are summarized.
Abstract: The article contains sections titled:
1 Introduction
2 Furfural
21 Properties
211 Physical Properties
212 Chemical Properties
22 Resources and Raw Materials
23 Production
231 Chemistry of Furfural Production
232 Production of Furfural
24 Uses and Economic Aspects
25 Quality Specifications, Transportation, Toxicology
3 Furfuryl Alcohol
31 Properties
311 Physical Properties
312 Chemical Properties
32 Resources and Raw Materials
33 Production
34 Uses and Economic Aspects
35 Quality Specifications, Transportation, Toxicology
4 Furan
41 Properties
42 Production
43 Uses, Economic Aspects, Transportation, Toxicology
5 Tetrahydrofurfuryl Alcohol
51 Properties
52 Production
53 Uses, Economic Aspects, Transportation, Toxicology
6 Furfurylamine and Tetrahydrofurfurylamine
7 Methylfuran and Methyltetrahydrofuran
8 Furoic acid
This article discusses the properties, production, and industrial uses of furfural and compounds derived from furfural on a commercial basis The only commercial route to furfural is acid-catalyzed digestion of pentosan sugars in biomass Nowadays, furfural is the sole precursor for all compounds containing a furyl, furfuryl, furoyl, or furfurylidene radical in the chemical industry
Detailed information is given on the production, properties, and economical aspects of furfural [98-01-1] and furfuryl alcohol [98-00-0], and the most important specialty chemicals derived from furfural and furfuryl alcohol are summarized: furan [110-00-9], tetrahydrofurfuryl alcohol [97-99-4], 3,4-dihydro-2H-pyran [110-87-2], furfurylamine [617-89-0], tetrahydrofurfurylamine [4795-29-3], 2-methylfuran [534-22-5], 2-methyltetrahydrofuran [96-47-9], and furoic acid [88-14-2]
177 citations
TL;DR: In this paper, a catalytic amount of TBATB in dichloromethane at room temperature is used to achieve tetrahydropyranylation to the parent alcohol.
89 citations
TL;DR: A comparison of ring-Opening Reactions and Multicomponent Reactions shows the importance of knowing the carrier and removal status of canine coronavirus, as a source of infection for humans and animals.
Abstract: 5.3. Miscellaneous Electrophilic Reactions 3519 6. Protection and Deprotection Reactions 3519 6.1. Alcohols 3520 6.1.1. Esters 3520 6.1.2. Ethers 3522 6.2. Carbonyls 3523 6.2.1. Acetals 3523 6.2.2. Acylals 3524 6.2.3. 1,3-Dicarbonyls (Enol Ethers and Enaminones) 3525 6.2.4. Imines, Hydrazones, and Oximes 3525 6.3. Amines 3526 7. Three-Membered Ring Reactions 3526 7.1. Epoxides 3526 7.2. Aziridines 3528 7.3. Seleniranium Ion 3528 8. Ring Synthesis 3528 8.1. Four-Membered Rings 3528 8.2. Five-Membered Rings 3529 8.3. Six-Membered Rings 3533 8.4. Seven-Membered Rings 3539 8.5. Nazarov Reaction 3539 9. Miscellaneous 3540 9.1. Multicomponent Reactions (MCRs) 3540 9.2. Polymerizations 3542 9.3. Oxidations 3542 9.4. Carbonyl Activation 3543 9.5. Substitution Reactions 3545 9.6. Synthesis of Salts 3545 9.7. Ring-Opening Reactions 3546 10. Conclusion 3546 11. Abbreviations 3546 12. References 3546
86 citations
References
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01 Jan 1981
TL;DR: In this article, the most useful groups for the hydroxyl, amino, carboxyl, carbonyl, and sulfhydryl groups are discussed and the chemistry of the classes of these groups, as well as that of individual groups within the class using structures, equations and references.
Abstract: Provides comprehensive information on the most useful protective groups for the hydroxyl, amino, carboxyl, carbonyl, and sulfhydryl groups. Discusses the chemistry of the classes of protective groups, as well as that of the individual protective groups within the class using structures, equations and references. Reactivity Charts for each class of protective group serve as an aid in their appropriate choice and provide estimates of their relative reactivities toward 108 prototype reagents.
14,841 citations
108 citations
TL;DR: In this article, aldehydes and acetals were converted to acyclic and cyclic dithioacetals in 5 M lithium perchlorate/diethyl ether (LPDE) medium at ambient temperature in high yields.
Abstract: Aldehydes and acetals were very efficiently converted to acyclic and cyclic dithioacetals in 5 M lithium perchlorate/diethyl ether (LPDE) medium at ambient temperature in high yields. Spectroscopic and other experimental evidences strongly suggest the formation of oxocarbenium ion intermediates from acetals in 5 M LPDE which subsequently reacted with thiols to give the dithioacetals. Under the same conditions keto- nes and their acetals also reacted, albeit very slowly compared to al- dehydes and acetals, to yield dithioacetals. The difference in their reactivity was successfully employed in the chemoselective dithioace- talization of aldehydes and acetals in the presence of ketones and their acetals
77 citations
TL;DR: The ring opening reaction of epoxides is investigated, and high chemo-, regioselectivity, and stereoselectivities have been reported.
Abstract: Epoxides are useful substrates in organic synthesis due to their high reactivity.1 Conversion of an epoxide to a carbonyl compound is a synthetically useful reaction, and BF3 and its etherate are the most commonly used reagents for this purpose.2 Unless there is a structural or a stereochemical bias, generally multiple products are obtained due to the lack of regioselectivity in the ring opening step. Moreover, lack of chemoselectivity among various substituted epoxides limits the synthetic utility of this reaction in multistep synthesis. In fact, no epoxide has been reported to be insensitive to BF3. Lithium and magnesium halides have been used for epoxide ring opening reaction.2-4 Recently, chemo and regioselective isomerization of epoxides to carbonyl compounds by a palladium catalyst has been reported.5 Lithium perchlorate in refluxing benzene has been reported to be a very useful reagent for the rearrangement of several epoxides as it shows higher product selectivity compared to strong Lewis acids.2,3,6 Recently, 5 M lithium perchlorate in diethyl ether (LPDE) has been shown to be an excellent medium for several synthetic transformations, and high chemo-, regio-, and stereoselectivities have been reported.7 In our efforts to use this medium for selective synthetic transformations,8,9 we have investigated the ring opening reaction of epoxides, and herein we report our results.
74 citations
TL;DR: In this article, a simple and efficient method for the synthesis of β-hydroxy nitriles by the direct opening of 1,2-epoxides with KCN in acetonitrile, in the presence of metal salts, is described.
62 citations