136889-92-4Relevant academic research and scientific papers
New total synthesis of (±)-chuangxinmycin
Kato, Keisuke,Ono, Machiko,Akita, Hiroyuki
, p. 1805 - 1808 (1997)
(±)-4'-Iodoindolmycenate 6 was stereoselectively converted into the (±)-(2,3)-syn-2-thioacetoxy ester 16 with retention of C2-stereochemistry in (±)-6. Palladium-catalysed cyclisation of indolyl iodide and the internal C2 thiol group of the substrate (±)-17 derived from (±)-16 gave the (±)-cis methyl ester 2 of natural chuangxinmycin (1).
Kinetic Resolution of Racemic Aldehydes through Asymmetric Allenoate γ-Addition: Synthesis of (+)-Xylogiblactone A
Park, Saehansaem,Pak, Gyungah,Oh, Changhwa,Lee, Jieun,Kim, Jimin,Yu, Chan-Mo
supporting information, p. 7660 - 7664 (2019/10/02)
A synthesis of (+)-xylogiblactone A has been achieved from t-butyl 2-methylbuta-2,3-dienoate in a linear three-step sequence. The key elements of the synthesis include a kinetic resolution of racemic 2-silyoxyaldehyde through the allenoate γ-addition to y
New total synthesis of (±)-, (-)- and (+)-chuangxinmycins
Kato, Keisuke,Ono, Machiko,Akita, Hiroyuki
, p. 10055 - 10062 (2007/10/03)
(±)-2-Hydroxy-3-(1H-4′-iodoindol-3′-yl)butanoate 6 was stereoselectively converted into the (±)-(2,3)-syn-2-thioacetoxy ester 13 with retention of C2-stereochemistry in (±)-6. Palladium-catalyzed cyclization of indolyl iodide and the internal C2 thiol group of the substrate (±)-14 gave the (±)-cis methyl ester 2 of natural chuangxinmycin (1). Stereoselective total syntheses of (-)-(4S,5R)- and (+)-(4R,5S)-chuangxinmycins 1 were achieved based on the enzymatic syntheses of (2R,3S)- and (2S,3R)-epoxy butanoates 9, respectively. Chiral intermediates such as (2R,3S)- and (2S,3R)-2-hydroxy-3-(1H-4′-iodoindol-3′-yl)butanoate 6 for the chiral synthesis of (-)- and (+)-1 were also obtained by the enantioselective hydrolysis of the corresponding acetate (±)-16 by lipase.
Synthesis and Reactions of 3-Hydroxy-2-nosyloxy Esters Produced by the Stereoselective Reduction of 2-Nosyloxy-3-keto Esters
Hoffman, Robert V.,Kim, Hwa-Ok
, p. 6759 - 6764 (2007/10/02)
The reduction of 2-nosyloxy-3-keto esters is an effective method for the preparation of 3-hydroxy-2-nosyloxy esters.The reduction is stereoselective for the syn isomer.The anti isomer can be produced as the major product by the addition of p-nitrobenzenesulfonyl peroxide to ketene bis-silyl acetal derivatives of 3-hydroxy esters.The diastereomers are separable chromatographically and can be converted stereospecifically to glycidic esters and 2-azido-3-hydroxy esters.As such they appear to have excellent potential as versatile synthetic intermediates for the synthesis of 1,2,3-trifunctional substances.
A stereocontrolled approach to electrophilic epoxides
Meth-Cohn, Otto,Moore, Clive,Taljaard, Heinrich C.
, p. 2663 - 2674 (2007/10/02)
Lithium t-butyl hydroperoxide (easily generated by addition of an alkyl-lithium to anhydrous t-butyl hydroperoxide in THF solution) is a powerful reagent for the epoxidation of electrophilic alkenes at -20 to 0 °C under full stereocontrol. Thus αβ-unsaturated esters, sulphones, sulphoximines, and amides are readily epoxidised with complete regio- and stereo-specificity and with considerable chiroselectivity (20-100%) when appropriate chiral auxiliaries such as menthyl, 8-phenylmenthyl, or a camphor-sulphonamide derivative are used. Asymmetric αβ-unsaturated sulphoximines undergo epoxidation with 100% diastereoselectivity. The only exceptions to stereocontrol noted are heavily substituted maleate esters such as di-t-butyl maleate. The αβ-epoxy amides are shown to be valuable sources of the corresponding epoxy ketones by treatment with an organolithium, allowing a stereo- and chemoselective entry in high yield to these useful intermediates.
Regioselective AlPO4-Al2O3 Promoted Ring-Opening of 2,3-Epoxy Esters
Riego, Juan,Costa, Antonio,Saa, Jose Manuel
, p. 1565 - 1568 (2007/10/02)
Synthesic AlPO4-Al2O3 promotes regioselective ring-opening of 2,3-epoxy esters by some oxygen and sulphur nucleophiles.Ritter type ring-opening with acetonitrile allowed the regioselective introduction of the acetamido group.
A Powerful New Stereo-controlled Method for Epoxidation of Electrophilic Alkenes
Clark, Carol,Hermans, Patricia,Meth-Cohn, Otto,Moore, Clive,Taljaard, Heinrich C.,Vuuren, Gerda van
, p. 1378 - 1380 (2007/10/02)
t-Butyl hydroperoxide and an alkyl-lithium in dry tetrahydrofuran are shown to epoxidise α,β-unsaturated esters and sulphones efficiently in a stereo- and regio-specific manner, while esters of chiral alcohols undergo diasterefacially selective epoxidatio
Enantioselective Diastereospecific Synthesis of anti-α-Alkyl-β-hydroxy Esters through Cuprate Opening of Glycidic Esters
Mulzer, Johann,Lammer, Ortrud
, p. 2178 - 2190 (2007/10/02)
A diastereospecific chain elongation of the aldehydes 1 to anti-αalkyl-β-hydroxy esters 2 via the intermediates 4 - 7 is described.By means of the Sharpless epoxidation, 2 may be obtained with >90percent ee in either enantiomer.
