- Access to a Key Building Block for the Prostaglandin Family via Stereocontrolled Organocatalytic Baeyer–Villiger Oxidation
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A new protocol for the construction of a crucial bicyclic lactone of prostaglandins using a stereocontrolled organocatalytic Baeyer–Villiger (B-V) oxidation was developed. The key B-V oxidation of a racemic cyclobutanone derivative with aqueous hydrogen peroxide has enabled an early-stage construction of a bicyclic lactone skeleton in high enantiomeric excess (up to 95 %). The generated bicyclic lactone is fully primed with two desired stereocenters and enabled the synthesis of the entire family of prostaglandins according to Corey′s route. Furthermore, the reactivity and enantioselectivity of B-V oxidation of racemic bicyclic cyclobutanones were evaluated and 90–99 % ee was obtained, representing one of the most efficient routes to chiral lactones. This study further facilitates the synthesis of prostaglandins and chiral lactone-containing natural products to promote drug discovery.
- Zhu, Kejie,Hu, Sha,Liu, Minjie,Peng, Haihui,Chen, Fen-Er
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supporting information
p. 9923 - 9927
(2019/05/16)
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- Methods for treating leukemia and myelodysplastic syndrome, and methods for identifying agents for treating same
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The present disclosure relates to methods for treating leukemia, pre-leukemic conditions, as well as myelodysplastic syndrome and acute myelogenous leukemia. The present disclosure further relates to compounds that can be used for treating leukemia, pre-leukemic conditions, as well as myelodysplastic syndrome and acute myelogenous leukemia. The present disclosure also relates to methods for identifying compounds that can be used for treating leukemia, pre-leukemic conditions, as well as myelodysplastic syndrome.
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- First total synthesis of A2 isoprostane
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A stereoselective Julia-Lythgoe olefination has allowed the first total synthesis of A2 isoprostane (1), a recently discovered member of the growing isoprostane family. This elusive compound opens up numerous new avenues for the molecular biology of cyclopentenone prostaglandins, which are endowed of intriguing biological effects such as antitumor, antiinflammatory, and antiviral activities.
- Zanoni, Giuseppe,Porta, Alessio,Vidari, Giovanni
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p. 4346 - 4351
(2007/10/03)
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- Lipase-catalysed acylation of prostanoids
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Natural prostaglandins (PG) F(2α) and E1 as well as (+)-cloprostenol were regioselectively 11-acylated using Novozym 435 as a catalyst and vinyl acetate as an acyl donor. Unlike the above compounds the 15-OH group of PGE2 was also acylated with a significant velocity under the same conditions. The enantiospecificity of the lipase-catalysed 11-acetylation of cloprostenol was established by separate treatment of (+)- and (-)-cloprostenols.
- Parve, Omar,Jaerving, Ivar,Martin, Ivar,Metsala, Andrus,Vallikivi, Imre,Aidnik, Madis,Pehk, Tonis,Samel, Nigulas
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p. 1853 - 1858
(2007/10/03)
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- Facile Retro Diels-Alder Reaction of a Pentamethyltricyclo2,6>decenone Derivative: Synthesis of (+)-15(S)-Prostaglandin A2
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The incorporation of methyl groups into the C(1), C(7), C(8), C(9), and C(10) positions of tricyclo2,6>decenone (1) dramatically accelerates the retro Diels-Alder reaction of (3) under Lewis acid catalysis thus permitting access to synt
- Grieco, Paul A.,Abood, Norman
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p. 410 - 412
(2007/10/02)
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- BIOSYNTHESIS OF 8-R-HPETE AND PRECLAVULONE-A FROM ARACHIDONATE IN SEVERAL SPECIES OF CARIBBEAN CORAL. A WIDESPREAD ROUTE TO MARINE PROSTANOIDS.
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The Caribbean coral species Plexaura homomalla, Plexaura nina, Plexaura flexuosa, Pseudopterogorgia americana, Muriceopsis flavida, and Eunicea asperula have all been found to convert arachidonate to 8-R-HPETE (4) and preclavulone-A (3) demonstrating that this route to marine prostanoids is widespread among such coral.
- Corey, E. J.,Matsuda, Seiichi P.T.,Nagata, Ryu,Cleaver, Martin B.
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p. 2555 - 2558
(2007/10/02)
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- A Triply Convergent Total Synthesis of L-(-)-Prostaglandin E2
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This paper details a versatile and efficient total synthesis of l-(-)-PGE2 (3).The key step is a triply convergent conjugate-addition/alkylation reaction involving the 1,4-addition of chiral vinyllithium reagent 7b to chiral vinyl sulfone D-47 to afford sulfone-stabilized anion , which is subsequently alkylated to produce the basic prostaglandin E2 skeleton 70.The synthesis of chiral vinyl sulfone D-47 involves a five step sequence with an enantioconvergent resolution process as one step and produces vinyl sulfone D-47 from readily available sulfide alcohol DL-11 in an overall yield of 36percent.The preparation of D-47 features two steps that utilize stereospecific SN2'reactions.The synthesis of l-(-)-PGE2 (3) involves a seven-step sequence from vinyl sulfone D-47 using mild conditions with an overall yield of 40percent and features an efficient peracetic acid oxidation of secondary amino acid 120 to oximino acid 121, which is, in turn, desulfonylated by 1,4-elimination of phenylsulfinic acid to generate a vinyl nitroso species that undergoes stereospecific 1,4-reduction by sodium borohydride to yield oxime 131.The hydrolysis of oxime 131 to l-(-)-PGE2 (3) using boron trifluoride and paraformaldehyde is the first reported high-yield method (84percent).This gives an overall yield for the synthesis of l-(-)-PGE2 (3) from racemic sulfide alcohol DL-11 of 14.5percent, including the resolution process.
- Donaldson, R. E.,Saddler, J. C.,Byrn, S.,McKenzie, A. T.,Fuchs, P. L.
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p. 2167 - 2188
(2007/10/02)
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- Total Synthesis of Prostaglandin A2 involving the Reaction of a Heterocuprate Reagent with an Allyl Epoxide
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A new route to prostaglandin A2 (18) involves as the key step the SN' anti reaction of the allyl epoxide (12) and the cuprate reagent (9).
- Chapleo, Christopher B.,Finch, Mark A. W.,Lee, Thomas V.,Roberts, Stanley M.,Newton, Roger F.
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p. 2084 - 2087
(2007/10/02)
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