41547-22-2Relevant articles and documents
New Sigmatropic Sequences Based on the Wittig Rearrangement of Bis-Allylic Ethers. Regiocontrolled Joining Reactions of Two or Three Allylic Moieties Leading to Unsaturated Carbonyl Compounds
Mikami, K.,Taya, S.,Nakai, T.,Fujita, Y.
, p. 5447 - 5449 (1981)
Three new sigmatropic sequences based on the Wittig rearrangement of bis-allylic ethers are described which provide unique, regiocontrolled methods for the synthesis of a variety of unsaturated carbonyl compounds possessing interesting molecular frameworks.
A Simple, Mild and General Oxidation of Alcohols to Aldehydes or Ketones by SO2F2/K2CO3 Using DMSO as Solvent and Oxidant
Zha, Gao-Feng,Fang, Wan-Yin,Leng, Jing,Qin, Hua-Li
supporting information, p. 2262 - 2267 (2019/04/17)
A practical, general and mild oxidation of primary and secondary alcohols to carbonyl compounds proceeds in yields of up to 99% using SO2F2 as electrophile in DMSO as both the oxidant and the solvent at ambient temperature. No moisture- and oxygen-free conditions are required. Stoichiometric amount of inexpensive K2CO3, which generates easy to separate by-products, is used as the base. Thus, 5-gram scale runs proceeded in nearly quantitative yields by a simple filtration as the work-up. The use of a polar solvent such as DMSO, which usually promotes competing Pummerer rearrangement, is also noteworthy. This protocol is compatible with a variety of common N-, O-, and S-functional groups on (hetero)arene, alkene and alkyne substrates (68 examples). The protocol was applied (99% yield) to a formal synthesis of the important cholesterol-lowering drug Rosuvastatin. (Figure presented.).
UNIQUE HALOGEN-INDUCED CYCLIZATIONS, REAGENTS THEREFOR, AND COMPOUNDS PRODUCED THEREBY
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Page/Page column 126-127, (2012/04/04)
This disclosure is related to halonium compounds useful for cyclization of polyenes, alkenoic acids, and alkenyl alkyl ethers, and halogenation of aromatic compounds. The synthesis of such halonium compounds, compounds made using such halonium compounds, and synthesis of natural compounds, including decalins, using the halonium compounds is also disclosed. A representative halonium compound of the disclosure is: Formula (I).
Production of pheromones and fragrances from substituted and unsubstituted 1-alken-3yl alkylates
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Page/Page column 7-8, (2010/05/13)
Compounds of the formula (I) wherein R2 is a branched or unbranched, saturated or ethylenically mono or di unsaturated aliphatic radical, Z is —CH2OH, —CH2OAc or —CHO, m is a whole positive integer of one or more, and Ac is an acetyl group are synthesized by a process wherein a 1-alken-3-yl alkylate, is reacted with a halo alkanol Grignard reagent.
Hydrazides as tunable reagents for alkene hydroamination and aminocarbonylation
Roveda, Jean-Gregoire,Clavette, Christian,Hunt, Ashley D.,Gorelsky, Serge I.,Whipp, Christopher J.,Beauchemin, Andre M.
supporting information; experimental part, p. 8740 - 8741 (2009/12/04)
(Chemical Equation Presented) Benzoic hydrazides (R = Ph), which are remarkably bench and thermally stable reagents (often up to 230°C), afford intramolecular hydroamination products upon heating at high temperatures (120-235°C). A concerted Cope-type hydroamination event, followed by a hydrazide-mediated proton transfer step of the hydrazinium ylide intermediate, is proposed and supported by DFT calculations. In contrast, a simple modification of the reagent structure (R = Ot-Bu or NH2) favors the formation of aminocarbonylation products at 200°C, and the latter reaction is shown to be stereospecific. Copyright
Stereoselective synthesis of cis-2,6-bis-hydroxyalkyl-tetrahydropyrans by the permanganate promoted oxidative cyclisation of 1,6-dienes
Cecil, Alex R.L.,Brown, Richard C.D.
, p. 7269 - 7271 (2007/10/03)
The first examples of permanganate promoted oxidative cyclisations of 1,6-dienes are described, providing exclusively cis-2,6-bis-hydroxyalkyl- tetrahydropyrans. In addition, good levels of asymmetric induction have been attained using dienoyl sultam substrates.
Intramolecular epoxidation in unsaturated ketones and oxaziridines
Armstrong,Draffan
, p. 2861 - 2873 (2007/10/03)
The possibility of intramolecular epoxidation in acyclic unsaturated ketones (via dioxiranes) and oxaziridines (via oxaziridinium species) has been investigated. Treatment of several acyclic unsaturated ketones with Oxone led to low levels of regio- and stereocontrol, suggesting that background epoxidation by Oxone dominates. However, treatment of unsaturated oxaziridines with methyl trifluoromethanesulfonate led to intramolecular epoxidation. This process allowed regioselective epoxidation of a non-conjugated diene. It also proceeded with a high degree of stereocontrol consistent with a stereoelectronic preference for aspiro-transition state.
NEW SIGMATROPIC SEQUENCES BASED ON THE -WITTIG REARRANGEMENT OF THE BIS ALLYLIC ETHER SYSTEM A GENERAL APPROACH TO REGIOCONTROLLED C-C BOND FORMATION OF ALLYLIC MOIETIES LEADING TO UNSATURATED CARBONYL COMPOUNDS
Mikami, Koichi,Kishi, Naoyuki,Nakai, Takeshi,Fujita, Yoshiji
, p. 2911 - 2918 (2007/10/02)
Four new sigmatropic sequences triggered by the regiocontrolled -Wittig rearrangement of unsymmetrical bis-allylic ethers (1) to the 1,5-dien-3-ols (2) are described, which provide unique, regiocontrolled methods for the synthesis of a wide variety of unsaturated carbonyl compounds possessing interesting molecular frameworks.The newly developed sequences include the -Wittig-Claisen, the tandem -Wittig-oxy-Cope, the tandem oxy-Cope-Claisen, and the tandem oxy-Cope-Cope sequences.