26118-97-8Relevant articles and documents
Efficient synthesis of sordidin, a male pheromone compound emitted by Cosmopolites sordidus
Ducrot, Paul-Henri
, p. 3923 - 3928 (1996)
A multigram-scale synthesis of sordidin ((1S*,3R*,5R*,7S*) 2,8-dioxa 1-ethyl 3,5,7-trimethyl bicyclo [3,2,1] octane) is described. Sordidin is obtained as a racemic mixture of its four isomers 1a-d (10 steps, 27% overall yield).
Formation, Alkylation, and Hydrolysis of Chiral Nonracemic N-Amino Cyclic Carbamate Hydrazones: An Approach to the Enantioselective α-Alkylation of Ketones
Huynh, Uyen,McDonald, Stacey L.,Lim, Daniel,Uddin, Md. Nasir,Wengryniuk, Sarah E.,Dey, Sumit,Coltart, Don M.
, p. 12951 - 12964 (2018/11/30)
The α-alkylation of ketones is a fundamental synthetic transformation. The development of asymmetric variants of this reaction is important given that numerous natural products, drugs, and related compounds exist as α-functionalized ketones or derivatives thereof. We previously reported our preliminary studies on the development of a new enantioselective ketone α-alkylation procedure using N-amino cyclic carbamate (ACC) auxiliaries. In comparison to other auxiliary-based methods, ACC alkylation offers a number of advantages and is both highly enantioselective and high yielding. Herein, we provide a full account of our studies on the enantioselective ACC ketone α-alkylation method.
On the regioselectivity and diastereoselectivity of ACC hydrazone alkylation
Huynh, Uyen,Uddin, Md. Nasir,Wengryniuk, Sarah E.,McDonald, Stacey L.,Coltart, Don M.
supporting information, p. 432 - 436 (2017/01/13)
The asymmetric α-allylation of 3-pentanone using several different N-amino cyclic carbamate (ACC) auxiliaries is described. The level of asymmetric induction was found to range from er?=?93:7 to er?=?99:1. The factors that lead to compromised selectivity
Investigation of a novel diamine based chiral auxiliary in the asymmetric alkylation of ketones
Clarke, Sarah L.,McSweeney, Christina M.,McGlacken, Gerard P.
, p. 356 - 361 (2014/04/03)
A novel chiral auxiliary containing a pyrrolidine ring has been utilised in the preparation of various chiral ketones with good to excellent enantioselectivities (up to 92%). It has been successfully employed in aldol and Michael reactions giving moderate to high selectivity.
Origins of stereoselectivity in the α-alkylation of chiral hydrazones
Krenske, Elizabeth H.,Houk,Lim, Daniel,Wengryniuk, Sarah E.,Coltart, Don M.
supporting information; experimental part, p. 8578 - 8584 (2011/03/20)
Density functional theory calculations and experiment reveal the origin of stereoselectivity in the deprotonation-alkylation of chiral N-amino cyclic carbamate (ACC) hydrazones. When the ACC is a rigid, camphor-derived carbamate, the two conformations of the azaenolate intermediate differ in energy due to conformational effects within the oxazolidinone ring and steric interactions between the ACC and the azaenolate. An electrophile adds selectively to the less-hindered π-face of the azaenolate. Although it was earlier reported that use of ACC auxiliaries led to α-alkylated ketones with er values of 82:18 to 98:2, B3LYP calculations predict higher stereoselectivity. Direct measurement of the dr of an alkylated hydrazone prior to removal of the auxiliary confirms this prediction; the removal of the auxiliary under the reported conditions can compromise the overall stereoselectivity of the process.
Sequenced Reactions with Samarium(II) Iodide. Domino Epoxide Ring-Opening/Ketyl Olefin Coupling Reactions
Molander, Gary A.,Losada, Carlos Del Pozo
, p. 2935 - 2943 (2007/10/03)
A new sequential reductive coupling process promoted by samarium(II) iodide is described. Cascade epoxide ring opening and ketyl radical olefin cyclization leads to a variety of cis-1,3-cyclopentanediols and cis-1,3-cyclohexanediols in good yields and with high diastereoselectivity.
Cerium(III) Chloride Mediated Michael Addition of RMgX to Nitroenes: a Very Efficient Access to Complex Nitroalkanes
Bartoli, Giuseppe,Bosco, Marcella,Sambri, Letizia,Marcantoni, Enrico
, p. 8651 - 8654 (2007/10/02)
Reactions of RMgX-CeCl3 complexes with nitroenes lead to functionalized nitroalkanes in very good yields.
Neighboring group participation in Lewis acid-promoted [3 + 4] and [3 + 5] annulations. The synthesis of oxabicyclo[3.n.1]alkan-3-ones
Molander, Gary A.,Camera, Kimberly O.
, p. 830 - 846 (2007/10/02)
Lewis acids are employed as catalysts in the annulation of 1,4- and 1,5-dicarbonyl dielectrophiles with bis(trimethylsilyl) end ethers of β-diketones and β-keto esters. A variety of 2-(alkoxycarbonyl)-m-oxabicyclo[3.n.1]alkan-3-ones can be constructed by this process in which two new carbon-carbon bonds are generated. Unusually high regiocontrol is observed, and good to excellent stereochemical control can be achieved at virtually every position on the new carbocycles. Intramolecular neighboring group participation is proposed to explain the unusually high selectivities attained in the annulation reaction.
Regioselective Aza-Cope Rearrangement of α-Halogenated and Nonhalogenated Imines
Welch, John T.,Corte, Bart De,Kimpe, Norbert De
, p. 4981 - 4983 (2007/10/02)
The 3-aza-Cope rearrangement of α-halogenated and nonhalogenated ketimines by deprotonation of the corresponding iminium salts was found to be an especially facile and regioselective process.Deuterium labeling studies supported the proposed mechanism which required the rearrangement to be highly concerted.
PALLADIUM(II)-CATALYZED CLAISEN REARRANGEMENT OF ALLYL VINYL ETHERS
Baan, J. L. van der,Bickelhaupt, F.
, p. 6267 - 6270 (2007/10/02)
The Claisen rearrangement of allyl vinyl ethers is catalyzed by PdCl2(CH3CN)2, provided that alkyl substituents protect the vinyl ether double bond from coordination by the metal catalyst.
