Strategies for the synthesis of brevipolides

• Yudhi D. Kurniawan and
• A'liyatur Rosyidah

Beilstein J. Org. Chem. 2021, 17, 2399–2416, doi:10.3762/bjoc.17.157

• followed by addition of TBSOTf at low temperature successfully formed the (Z)-silyl enol ether 54. Application of the Sharpless asymmetric dihydroxylation, promoted by AD-mix-β, gave the expected β-(R)-hydroxy cyclopropyl product 55 in 84% yield with moderate diastereoselectivity (dr = 2). The formation of

Vicinal difluorination as a C=C surrogate: an analog of piperine with enhanced solubility, photostability, and acetylcholinesterase inhibitory activity

• Yuvixza Lizarme-Salas,
• Alexandra Daryl Ariawan,
• Ranjala Ratnayake,
• Hendrik Luesch,
• Angela Finch and
• Luke Hunter

Beilstein J. Org. Chem. 2020, 16, 2663–2670, doi:10.3762/bjoc.16.216

• ] was protected as the benzyl ether then subjected to a Sharpless asymmetric dihydroxylation reaction to furnish the diol 8 in modest yield. The diol 8 was then converted into the cyclic sulfate 9, which was ring-opened using TBAF to furnish the fluorohydrin 10. A Mosher ester analysis of the

N-(1-Phenylethyl)aziridine-2-carboxylate esters in the synthesis of biologically relevant compounds

• Iwona E. Głowacka,
• Aleksandra Trocha,
• Andrzej E. Wróblewski and
• Dorota G. Piotrowska

Beilstein J. Org. Chem. 2019, 15, 1722–1757, doi:10.3762/bjoc.15.168

• (Scheme 37) [32]. The major product (2S,1'R)-69b was subjected to Sharpless asymmetric dihydroxylation in the presence of AD-mix-α to give the diol 145a as a major (10:1) diastereoisomer. The ester moiety in 145a was reduced and hydroxy groups were protected to give the tribenzyloxy aziridine (2R,1'S,2'S

The use of 4,4,4-trifluorothreonine to stabilize extended peptide structures and mimic β-strands

• Yaochun Xu,
• Isabelle Correia,
• Tap Ha-Duong,
• Nadjib Kihal,
• Jean-Louis Soulier,
• Julia Kaffy,
• Benoît Crousse,
• Olivier Lequin and
• Sandrine Ongeri

Beilstein J. Org. Chem. 2017, 13, 2842–2853, doi:10.3762/bjoc.13.276

• ] from propargylic alcohol in ten steps, based on the trifluoromethylation key step of 1-(((E)-3-bromoallyloxy)methyl)benzene to obtain (E)-1-benzyloxy-4,4,4-trifluoro-2-butene. The sequence then involved Sharpless asymmetric dihydroxylation, nucleophilic opening of cyclic sulfate with NaN3, palladium

Studies directed toward the exploitation of vicinal diols in the synthesis of (+)-nebivolol intermediates

• Runjun Devi and
• Sajal Kumar Das

Beilstein J. Org. Chem. 2017, 13, 571–578, doi:10.3762/bjoc.13.56

• Runjun Devi Sajal Kumar Das Department of Chemical Sciences, Tezpur University, Napaam, Tezpur, Assam-784028, India 10.3762/bjoc.13.56 Abstract While the exploitation of the Sharpless asymmetric dihydroxylation as the source of chirality in the synthesis of acyclic molecules and saturated

• heterocycles has been tremendous, its synthetic utility toward chiral benzo-annulated heterocycles is relatively limited. Thus, in the search for wider applications of Sharpless asymmetric dihydroxylation-derived diols for the synthesis of benzo-annulated heterocycles, we report herein our studies in the

• that a large number of racemic and asymmetric syntheses of nebivolol and their intermediates have been described in the literature, however, the Sharpless asymmetric dihydroxylation has never been employed as the sole source of chirality for this purpose. Keywords: dihydroxylation; epoxide-ring

The direct oxidative diene cyclization and related reactions in natural product synthesis

• Juliane Adrian,
• Leona J. Gross and
• Christian B. W. Stark

Beilstein J. Org. Chem. 2016, 12, 2104–2123, doi:10.3762/bjoc.12.200

• the key step (right, Scheme 8) [79]. After reduction of the ester 26, a Sharpless asymmetric dihydroxylation (AD) [86][87][88] reaction furnished diol 31 with a high degree of both regio- and enantioselectivity. Osmium-promoted oxidative type B cyclization of 31 proceeded in high yield (81%) and with

The total synthesis of D-chalcose and its C-3 epimer

• Jun Sun,
• Song Fan,
• Zhan Wang,
• Guoning Zhang,
• Kai Bao and
• Weige Zhang

Beilstein J. Org. Chem. 2013, 9, 2620–2624, doi:10.3762/bjoc.9.296

• C3 via Grignard reaction, the introduction of the stereogenic center on C2 by Sharpless asymmetric dihydroxylation, the protection of the C1 and C2 hydroxy groups with tert-butyldimethylsilyl trifluoromethanesulfonate (TBSOTf), and the selective cleavage of the primary OTBS ether using catalytic DL

• retrosynthetic analysis of I and I′ is presented in Scheme 1. Diol II and II′ arose from a Sharpless asymmetric dihydroxylation that form the C2 stereogenic center. The installation of the C3 stereocenter on vinyl ether III was proposed to utilize a Grignard reaction followed by chromatographic separation

• conditions [20]. Similarly, alcohol 4 could be converted to 4′. Alcohol 4 was methylated using MeI and t-BuOK to produce 5 in nearly quantitative yield (Scheme 3). Sharpless asymmetric dihydroxylation [21] of olefin 5 using AD-mix-β in a 1:1 mixture of t-BuOH/H2O at 0 °C over four days afforded diol 6 with S

Stereoselective synthesis of the C79–C97 fragment of symbiodinolide

• Hiroyoshi Takamura,
• Takayuki Fujiwara,
• Isao Kadota and
• Daisuke Uemura

Beilstein J. Org. Chem. 2013, 9, 1931–1935, doi:10.3762/bjoc.9.228

• Sharpless asymmetric dihydroxylation were utilized as the key transformations. Keywords: Julia–Kocienski olefination; polyol marine natural product; Sharpless asymmetric dihydroxylation; spiroacetalization; symbiodinolide; Findings A 62-membered polyol marine natural product, symbiodinolide (1, Figure 1

• the Birch reduction to afford the trans-alkene 6, wherein the benzyl moiety was deprotected. The alkene 6 was derivatized to the spiroacetal C79–C96 fragment 7 in four steps including the benzyl protection and Sharpless asymmetric dihydroxylation (AD). Although the desired spiroacetal fragment 7 was

• Information File 1). In conclusion, we have achieved the stereoselective synthesis of the C79–C97 fragment. The synthetic route has featured a stereoselective spiroacetalization, a Julia–Kocienski olefination, and a Sharpless asymmetric dihydroxylation. This synthesis of the spiroacetal fragment, wherein the

A new approach toward the total synthesis of (+)-batzellaside B

• Jolanta Wierzejska,
• Shin-ichi Motogoe,
• Yuto Makino,
• Tetsuya Sengoku,
• Masaki Takahashi and
• Hidemi Yoda

Beilstein J. Org. Chem. 2012, 8, 1831–1838, doi:10.3762/bjoc.8.210

• (+)-batzellaside B from naturally abundant L-pyroglutamic acid is presented in this article. The key synthetic step involves Sharpless asymmetric dihydroxylation of an olefinic substrate functionalized with an acetoxy group to introduce two chiral centres diastereoselectively into the structure. Heterocyclic

• transformation will involve Sharpless asymmetric dihydroxylation to install stereoselectively the hydroxy groups at C3 and C4 positions of the olefinic substrate 6, and an intramolecular cyclization of aldehyde generated in situ from 5 to construct the piperidine ring system. The present publication describes

Directed ortho,ortho'-dimetalation of hydrobenzoin: Rapid access to hydrobenzoin derivatives useful for asymmetric synthesis

• Inhee Cho,
• Labros Meimetis,
• Lee Belding,
• Michael J. Katz,
• Travis Dudding and
• Robert Britton

Beilstein J. Org. Chem. 2011, 7, 1315–1322, doi:10.3762/bjoc.7.154

• (S,S)-hydrobenzoin are relatively inexpensive [18], or can be readily prepared on kilogram-scale from trans-stilbene through Sharpless asymmetric dihydroxylation (SAD) [19][20], the synthesis of ortho,ortho'-functionalized derivatives of hydrobenzoin typically requires several steps that include

Can we measure catalyst efficiency in asymmetric chemical reactions? A theoretical approach

• Shaimaa El-Fayyoumy,
• Matthew H. Todd and
• Christopher J. Richards

Beilstein J. Org. Chem. 2009, 5, No. 67, doi:10.3762/bjoc.5.67

• anecdotally refer to a “good“ or “bad“ reaction, there is no system for comparing those reactions with each other. Well-known examples of asymmetric catalysis such as the Sharpless asymmetric dihydroxylation, the Corey oxazaborolidine ketone reduction or the proline-catalysed aldol reaction are almost

Recent progress on the total synthesis of acetogenins from Annonaceae

• Nianguang Li,
• Zhihao Shi,
• Yuping Tang,
• Jianwei Chen and
• Xiang Li

Beilstein J. Org. Chem. 2008, 4, No. 48, doi:10.3762/bjoc.4.48

• materials (e.g. amino acids, sugars, tartaric acid, etc.) or on asymmetric reactions {e.g. Sharpless asymmetric epoxidation (AE), Sharpless asymmetric dihydroxylation (AD), diastereoselective Williamson etherification, etc.}. Semi-synthesis of natural ACGs as well as derivatised ACGs (e.g. amines, esters

An asymmetric synthesis of all stereoisomers of piclavines A1-4 using an iterative asymmetric dihydroxylation

• Yukako Saito,
• Naoki Okamoto and
• Hiroki Takahata

Beilstein J. Org. Chem. 2007, 3, No. 37, doi:10.1186/1860-5397-3-37

• challenge. Our interest in this field has been focused on potential strategies based on the enantiomeric enhancement caused by the twofold or more application of the Sharpless asymmetric dihydroxylation (AD) [5][6] or Brown's asymmetric allylboration[7] reactions. In general, the enantiomeric excesses (ees