- Biocatalytic synthesis of chiral polyoxygenated compounds: Modulation of the selectivity upon changes in the experimental conditions
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Derivatives of both enantiomers of butane-1,2,4-triol have been obtained through a transesterification reaction catalyzed by Pseudomonas fluorescens lipase (PFL) in organic solvents. The influence of the solvent on the enantioselectivity has been thorough
- Herradon,Valverde
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Read Online
- Total Synthesis and Biological Evaluation of Siladenoserinol A and its Analogues
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The total synthesis of siladenoserinol A, an inhibitor of the p53–Hdm2 interaction, has been achieved. AuCl3-catalyzed hydroalkoxylation of an alkynoate derivative smoothly and regioselectively proceeded to afford a bicycloketal in excellent yield. A glycerophosphocholine moiety was successfully introduced through the Horner–Wadsworth–Emmons reaction using an originally developed phosphonoacetate derivative. Finally, removal of the acid-labile protecting groups, followed by regioselective sulfamate formation of the serinol moiety afforded the desired siladenoserinol A, and benzoyl and desulfamated analogues were also successfully synthesized. Biological evaluation showed that the sulfamate is essential for biological activity, and modification of the acyl group on the bicycloketal can improve the inhibitory activity against the p53–Hdm2 interaction.
- Yoshida, Masahito,Saito, Koya,Kato, Hikaru,Tsukamoto, Sachiko,Doi, Takayuki
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supporting information
p. 5147 - 5150
(2018/03/26)
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- Transacetalization of acetals with butane-1,2,4-triol using cobalt(II) chloride and chlorotrimethylsilane
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Transacetalization of acetals with butane-1,2,4-triol was carried out using cobalt(II) chloride and chlorotrimethylsilane as catalysts. The reaction occurs under mild conditions in acetonitrile and with a short reaction time. The synergic effect of the two Lewis acids catalyzes the conversion of butane-1,2,4-triol into (2-alkyl- or 2-aryl-1,3-dioxan-4-yl)methanol derivatives with high regiospecificity and diasteroselectivity. Georg Thieme Verlag Stuttgart · New York.
- Battisti, Umberto Maria,Sorbi, Claudia,Franchini, Silvia,Tait, Annalisa,Brasili, Livio
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p. 943 - 946
(2014/04/03)
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- Third-generation immucillins: Syntheses and bioactivities of acyclic immucillin inhibitors of human purine nucleoside phosphorylase
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ImmH (1) and DADMe-ImmH (2) are potent inhibitors of human purine nucleoside phoshorylase (PNP), developed by us and currently in clinical trials for the treatment of a variety of T-cell related diseases. Compounds 1 and 2 were used as templates for the design and synthesis of a series of acyclic immucillin analogues (8-38) in order to identify simplified alternatives to 1 and 2. SerMe-ImmG (8) and DATMe- ImmG (9) displayed the lowest inhibition constants of 2.1 and 3.4 pM, respectively, vs PNP. It was postulated that the flexible natures of 8 and 9 enabled them to adopt conformations resembling those of 1 and 2 within the active site of PNP and that the positioning of two hydroxyl groups was critical for picomolar activity. SerMe-ImmH (10, K d = 5.2 pM) was shown to be orally available in mice with a long biological residence time on blood PNP.
- Clinch, Keith,Evans, Gary B.,Frohlich, Richard F. G.,Furneaux, Richard H.,Kelly, Peter M.,Legentil, Laurent,Murkin, Andrew S.,Li, Lei,Schramm, Vern L.,Tyler, Peter C.,Woolhouse, Anthony D.
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experimental part
p. 1126 - 1143
(2010/02/16)
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- New and concise approach to (R)-α-lipoic acid
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A concise enantiospecific synthesis of (S)-6,8-bis(methylsulfonyloxy)- octanoic acid (2), a ready precursor of (R)-(+)-α-lipoic acid (1), is reported. The key step of the synthesis is the coupling of the tosylate derived from (R)-malic acid with phenylpro
- Wei, Zhen,Lan, Hong-Qiao,Zheng, Jian-Feng,Huang, Pei-Qiang
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experimental part
p. 691 - 701
(2009/07/18)
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- An enantiocontrolled synthesis of pyrrolizidines, (-)-platynecine and (-)-hadinecine
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Trisubstituted allylic alcohols 13 and 14 have been converted into a single isomeric trans-oxazoline 16 via an intramolecular iodoamidation of the corresponding trichloroacetimidates, which have been elaborated into (-)-platynecine 1 and(-)-hadinecine 2 via a common intermediate pyrrolizidine.
- Kang, Sung Ho,Kim, Geun Tae,Yoo, Yong Sang
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p. 603 - 606
(2007/10/03)
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- Stereoselective syntheses and reactions of chiral oxygenated α,β-unsaturated-γ- and δ-lactones
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The syntheses of the chiral α,β-unsaturated lactones (+)-5, (-)-6, (+)-8, (+)-9, and (+)-10 have been efficiently achieved from readily available starting materials. The lactone (+)-5 has been synthesized in 7 steps from (R,R)-dimethyl tartrate (38-43% overall yield). The use of (+)-5 in formal syntheses of natural (+)-asperlin 4 and advanced intermediates for (+)-olguine 2 are also reported. The lactone (-)-6 has been prepared in 5 steps from (R)-malic and (44-50% overall yield). It can be a useful precursor for the syntheses of branched chain and deoxy nucleoside analogues. The preparation of (-)-6 constitutes formal syntheses of natural (+)-eldanolide 53 and the (+)-Geissman-Waiss lactone 54 (an intermediate for the syntheses of a variety of pyrrolizidine alkaloids). The lactones (+)-8, (+)-9 and (+)-10 have been synthesized from 3,4-di-O-acetyl-L-rhamnal 58. The highly diastereoselective transformations of (+)-9 and (+)-10, through sequential conjugate nucleophilic addition and enolate reaction, into densely functionalized chiral γ-lactones 12 are also reported. Copyright (C) Elsevier Science Ltd.
- Sanchez-Sancho, Francisco,Valverde, Serafin,Herradon, Bernardo
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p. 3209 - 3246
(2007/10/03)
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- Regio- and enantioselective esterifications of polyoxygenated compounds catalyzed by lipases
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The lipase catalyzed esterifications of derivatives of propane-1,2,3-triol and butane 1,2,4-triol in organic solvents have been studied. The influence of several factors (lipase source, organic solvent, additives and structural variations in the substrate
- Herradon,Cueto,Morcuende,Valverde
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p. 845 - 864
(2007/10/02)
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- Lipase catalyzed kinetic resolution of (±)-cis-4-hydroxymethyl-2-phenyl-1,3-dioxane
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The title compound has been kinetically resolved through a lipase catalyzed transesterification in organic solvents. The influence of the enzyme source, as well as the nature of the solvent on the enantioselectivity have been studied.
- Herradon
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p. 209 - 212
(2007/10/02)
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- EFFICIENT SYNTHESIS OF (R)-5-(2-HYDROXYETHYL)-2(5H)-FURANONE FROM (R)-MALIC ACID
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The title compound has been synthesized in five steps, 48percent overall yield, from (R)-malic acid.
- Herradon, Bernardo
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p. 191 - 194
(2007/10/02)
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