Chiron approach to the synthesis of yashabushidiol B, (3S,5S)-1-(4′-hydroxyphenyl)-7-phenylheptane-3,5-diol, and its 4′-methoxy analogue

Pawar, Vishwas U.; Shinde, Vaishali

doi:10.1016/j.tetasy.2010.12.015

Cited by 15 publications

(4 citation statements)

References 19 publications

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“…It was possible to form the required target by sequential control of the reduction of each acetylenic ketone in turn. , The absolute configuration of the product 20 , as well as its precursors 21 and 22 , was confirmed by comparison of the sign of the optical rotations of these compounds with those reported (see Supporting Information). This also served to confirm the absolute configuration of the reduction product of 3a1 and hence the β-keto ester reductions in Table . The ee and dr of 20 were determined by comparison of the chiral HPLC spectrum with that of a racemic/meso product mixture.…”

Section: Resultsmentioning

confidence: 58%

“…An application of the reductive methodology directed by a triple bond adjacent to the ketone was found in the synthesis of (−)-yashabushidiol B 20 (Scheme ) . It was possible to form the required target by sequential control of the reduction of each acetylenic ketone in turn. , The absolute configuration of the product 20 , as well as its precursors 21 and 22 , was confirmed by comparison of the sign of the optical rotations of these compounds with those reported (see Supporting Information).…”

Section: Resultsmentioning

confidence: 76%

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Asymmetric Transfer Hydrogenation of Functionalized Acetylenic Ketones

Fang

Wills

2013

J. Org. Chem.

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Section: Resultsmentioning

confidence: 58%

Section: Resultsmentioning

confidence: 76%

Asymmetric Transfer Hydrogenation of Functionalized Acetylenic Ketones

Fang

Wills

2013

J. Org. Chem.

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“…The 2‐OH group in 8 was methylated using iodomethane and silver oxide, [14] affording 9 . Complete deprotection of 9 , under acidic conditions, [15] gave the known 2‐O‐methyl‐α,β‐ d ‐mannose 10 in 25 % yield (Scheme 2). Next, we coupled 10 with pyruvate using a sialic acid aldolase, by following published conditions, [16a,b] to give the desired 5‐ O ‐methyl‐Kdn in an estimated equilibrium conversion of 80 % (TLC analysis).…”

Section: Resultsmentioning

confidence: 99%

A Mechanistic Study on the Non‐enzymatic Hydrolysis of Kdn Glycosides

et al. 2022

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Sialic acids are biologically important carbohydrates that are prevalent throughout nature. We are interested in their intrinsic reactivity in aqueous solution and how such reactivity affects the design of substrates for investigation of enzymes that process these sugars. To probe the reactivity differences between two sialic acid family members N‐acetylneuraminic acid and Kdn we measured the rate constants for hydrolysis of 4‐nitrophenyl 3‐deoxy‐d‐glycero‐α‐d‐galacto‐non‐2‐ulosonide in aqueous solution. The kinetic data is consistent with glycosidic C−O bond cleavage occurring via four mechanistic pathways, and these are: (i) hydronium ion‐catalyzed hydrolysis of the neutral sugar; (ii) hydronium ion‐catalyzed hydrolysis of the glycosidic carboxylate; (iii) water‐catalyzed hydrolysis of the anionic glycoside; and (iv) base‐promoted reaction of the anionic glycoside. To study the effects of C‐5 substitution on the Kdn glycoside we made 4‐nitrophenyl 5‐O‐methyl‐α‐Kdn glycoside and determined its rate constants for hydrolysis. All hydrolytic rate constants for both Kdn glycosides were larger than those reported for the parent N‐acetyl‐α‐neuraminide. The water‐catalyzed reaction (pathway iii) exhibited a βlg value of −1.3±0.1. We conclude that the larger rate constants associated with C5‐oxygen containing sialosides results from less steric congestion at the hydrolytic transition states than for the parent C‐5 acetamido glycoside.

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“…Stereoselective synthesis of yashabushidiols and their derivatives has been reported by Venkateswarlu's group, Shinde's group, and Yikang's group [41][42][43]. Each group used a sugar or derivative as a starting material; for example, d-mannitol, d-glucose, and d-gluconolactone.…”

Section: Synthesis Of Diarylheptanoidsmentioning

confidence: 99%