The Experts below are selected from a list of 15 Experts worldwide ranked by ideXlab platform
Marian Mikołajczyk - One of the best experts on this subject based on the ideXlab platform.
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A new and expeditious synthesis of all enantiomerically pure stereoisomers of Rosaprostol, an antiulcer drug
Beilstein-Institut, 2016Co-Authors: Wiesława Perlikowska, Remigiusz Żurawiński, Marian MikołajczykAbstract:Four enantiomerically pure stereoisomers of Rosaprostol (1), an antiulcer drug, were efficiently synthesized from the enantiomers of 2-(dimethoxyphosphoryl)-3-hexylcyclopentanone (3) as chiral substrates. The latter were obtained by resolution of racemic 3 with (+)-(R)-1-(1-naphthyl)ethylamine. The conversion of (+)-3 into Rosaprostol stereoisomer (−)-1a was accomplished in four steps in 56% overall yield. According to the same protocol, the second stereoisomer (+)-1c was obtained from (−)-3 in 55% overall yield. A slightly improved procedure of the last two steps of the transformation of (+)-3 into (−)-1a allowed an increase in the overall yield to 64%. The remaining two stereoisomers, (−)-1b and (+)-1d, were obtained from (−)-1a and (+)-1c in 71 and 68% yield, respectively, by a two-reaction sequence, in which a Mitsunobu inversion of configuration at C-5 was the key step
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Synthesis of Enantiomerically Pure Stereomers of Rosaprostol
2015Co-Authors: Beata Łukasik, Wiesława Perlikowska, Remigiusz Żurawiński, Marian MikołajczykAbstract:Enantiopure stereomers of Rosaprostol 1, an antiulcer drug, were synthesized from diastereomeric building blocks (−)-5a and (+)-5b. Conversion of (−)-5a into Rosaprostol stereomer (−)-(1S,2R,5R)-1a was accomplished in nine steps in 18% overall yield. In this sequence, fully diastereoselective hydrogeneration of the endocyclic carbon double bond in the cyclopentenone ring was key, generating a new stereogenic center (C-2 in 1a). C-5 epimeric Rosaprostol (−)-(1S,2R,5S)-1b was obtained from (−)-1a in 72% yield by a two-reaction sequence involving methylation and one-pot Mitsunobu esterification–hydrolysis
Marian Mikolajczyk - One of the best experts on this subject based on the ideXlab platform.
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New phosphonate-mediated syntheses of cyclopentanoids and prostaglandins*
2015Co-Authors: Marian Mikolajczyk, Maciej Mikina, Remigiusz ZurawinskiAbstract:Abstract: This account outlines the results obtained in the author’s laboratory on the application of phosphonate reagents in the synthesis of biologically active cyclopentanones and cyclopentenones. The synthesis and reactivity of 3-phosphorylmethyl-cycloalkenones is discussed as a platform for developing the first synthesis of enantiomeric isoterreins as well as the synthesis of racemic and optically active prostaglandins B1a. A different strategy for the total synthesis of racemic and enantiomeric forms of sarkomycin and Rosaprostol is described which involves in a key step intramolecular carbenoid cyclization of the corresponding a-diazo-b-ketophosphonates
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phosphonate mediated synthesis of biologically active cyclopentanones and cyclopentenones
ChemInform, 2003Co-Authors: Marian MikolajczykAbstract:The synthesis and reactivity of 3-(phosphorylmethyl)cyclopent-2-enones as well as a complete desymmetrization of meso -tartaric acid are discussed as a platform for developing the synthesis of racemic Rosaprostol and enantiomeric forms of prostaglandin B 1 methyl ester, isoterrein, and neplanocin A.
Remigiusz Zurawinski - One of the best experts on this subject based on the ideXlab platform.
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New phosphonate-mediated syntheses of cyclopentanoids and prostaglandins*
2015Co-Authors: Marian Mikolajczyk, Maciej Mikina, Remigiusz ZurawinskiAbstract:Abstract: This account outlines the results obtained in the author’s laboratory on the application of phosphonate reagents in the synthesis of biologically active cyclopentanones and cyclopentenones. The synthesis and reactivity of 3-phosphorylmethyl-cycloalkenones is discussed as a platform for developing the first synthesis of enantiomeric isoterreins as well as the synthesis of racemic and optically active prostaglandins B1a. A different strategy for the total synthesis of racemic and enantiomeric forms of sarkomycin and Rosaprostol is described which involves in a key step intramolecular carbenoid cyclization of the corresponding a-diazo-b-ketophosphonates
Wiesława Perlikowska - One of the best experts on this subject based on the ideXlab platform.
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A new and expeditious synthesis of all enantiomerically pure stereoisomers of Rosaprostol, an antiulcer drug
Beilstein-Institut, 2016Co-Authors: Wiesława Perlikowska, Remigiusz Żurawiński, Marian MikołajczykAbstract:Four enantiomerically pure stereoisomers of Rosaprostol (1), an antiulcer drug, were efficiently synthesized from the enantiomers of 2-(dimethoxyphosphoryl)-3-hexylcyclopentanone (3) as chiral substrates. The latter were obtained by resolution of racemic 3 with (+)-(R)-1-(1-naphthyl)ethylamine. The conversion of (+)-3 into Rosaprostol stereoisomer (−)-1a was accomplished in four steps in 56% overall yield. According to the same protocol, the second stereoisomer (+)-1c was obtained from (−)-3 in 55% overall yield. A slightly improved procedure of the last two steps of the transformation of (+)-3 into (−)-1a allowed an increase in the overall yield to 64%. The remaining two stereoisomers, (−)-1b and (+)-1d, were obtained from (−)-1a and (+)-1c in 71 and 68% yield, respectively, by a two-reaction sequence, in which a Mitsunobu inversion of configuration at C-5 was the key step
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Synthesis of Enantiomerically Pure Stereomers of Rosaprostol
2015Co-Authors: Beata Łukasik, Wiesława Perlikowska, Remigiusz Żurawiński, Marian MikołajczykAbstract:Enantiopure stereomers of Rosaprostol 1, an antiulcer drug, were synthesized from diastereomeric building blocks (−)-5a and (+)-5b. Conversion of (−)-5a into Rosaprostol stereomer (−)-(1S,2R,5R)-1a was accomplished in nine steps in 18% overall yield. In this sequence, fully diastereoselective hydrogeneration of the endocyclic carbon double bond in the cyclopentenone ring was key, generating a new stereogenic center (C-2 in 1a). C-5 epimeric Rosaprostol (−)-(1S,2R,5S)-1b was obtained from (−)-1a in 72% yield by a two-reaction sequence involving methylation and one-pot Mitsunobu esterification–hydrolysis
Maciej Mikina - One of the best experts on this subject based on the ideXlab platform.
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New phosphonate-mediated syntheses of cyclopentanoids and prostaglandins*
2015Co-Authors: Marian Mikolajczyk, Maciej Mikina, Remigiusz ZurawinskiAbstract:Abstract: This account outlines the results obtained in the author’s laboratory on the application of phosphonate reagents in the synthesis of biologically active cyclopentanones and cyclopentenones. The synthesis and reactivity of 3-phosphorylmethyl-cycloalkenones is discussed as a platform for developing the first synthesis of enantiomeric isoterreins as well as the synthesis of racemic and optically active prostaglandins B1a. A different strategy for the total synthesis of racemic and enantiomeric forms of sarkomycin and Rosaprostol is described which involves in a key step intramolecular carbenoid cyclization of the corresponding a-diazo-b-ketophosphonates
