<i>d</i>‐Psicose

“…[α] D 20 =−2.4 . Data for d ‐psicose: +3.02 ( c =1.16 in H 2 O) [30] , +3.1 ( c =1.62 in H 2 O) . NMR data were identical to those previously described for the d enantiomer: (ratio α‐ d ‐psico‐2.6‐pyranose/β‐ d ‐psico‐2.6‐pyranose/α‐ d ‐psico‐2.5‐furanose/β‐ d ‐psico‐2.6‐furanose=25/24/37/13; lit.…”

Section: Methodsmentioning

confidence: 56%

Convergent in situ Generation of Both Transketolase Substrates via Transaminase and Aldolase Reactions for Sequential One‐Pot, Three‐Step Cascade Synthesis of Ketoses

et al. 2019

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We describe an efficient three-enzyme, sequential one-pot cascade reaction where both transketolase substrates are generated in situ in a convergent fashion. The nucleophilic donor substrate hydroxypyruvate was obtained from l-serine and pyruvate by a transaminase-catalyzed reaction. In parallel, three different (2S)-α-hydroxylated aldehydes, l-glyceraldehyde, d-threose, and l-erythrose, were generated as electrophilic acceptors from simple achiral compounds glycolaldehyde and formaldehyde by d-fructose-6-phosphate aldolase catalysis. The compatibility of the three enzymes was studied in terms of temperature, enzyme ratio and substrate concentration. The efficiency of the process relied on the irreversibility of the transketolase reaction, driving a shift of the reversible transamination reaction and securing the complete conversion of all substrates. Three valuable (3S,4S)-ketoses, l-ribulose, d-tagatose, and l-psicose were obtained in good yields with high diastereoselectivity.

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“…Recrystallizations from aqueous methanol gave needles, m.p, 165-7°, (oc):i+128°(reported 166.5-8° [10]; 167-8°, (oc)D+124°(chloroform) [2]). Concentration of the filtered solution until crystallization commenced (to about 600 m1 and then 200 m1) afforded 11.5 g of crude 11P,17IX,21-trihydroxy-5IX-pregnane-3,20-dione (fa).…”

Section: Hydrogenation Of Hydrocortisonementioning

confidence: 99%

Studies in Syntheses of Steroid Metabolites. I.

Harnik¹

1963

Israel Journal of Chemistry

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Several approaches to the synthesis of 3α, 11β‐dihydroxy‐5α‐androstane‐17‐one (Vila) and 3α‐hydroxy‐5α‐androstane‐11,17‐dione (XIIa) are discussed. The preferred route involves selective sodium borohydride reduction of 5α‐androstane‐3,11,17‐trione (V) to 3β‐hydroxy‐5α‐androstane‐11,17‐dione (VIa) and solvolysis of its tosylate (VIc) to afford a mixture of the ketoalcohol (XIIa) and the olefin (VIIIb). The latter is then converted, through the ketals (XIb) and (XIIIb), into the diolone (VIIa).

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d‐Psicose

Cited by 57 publications

References 3 publications

Chemistry of the Carbohydrates and Glycosides

Chemistry of the Carbohydrates and Glycosides

Convergent in situ Generation of Both Transketolase Substrates via Transaminase and Aldolase Reactions for Sequential One‐Pot, Three‐Step Cascade Synthesis of Ketoses

Studies in Syntheses of Steroid Metabolites. I.

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