- Optically pure γ-butyrolactones and epoxy esters via two stereocentered HKR of 3-substituted epoxy esters: A formal synthesis of (-)-paroxetine, Ro 67-8867 and (+)-eldanolide
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The HKR of racemic anti- or syn-3-substituted epoxy esters catalyzed by a Co(iii)salen complex provides ready access to the corresponding enantioenriched 3,4-disubstituted γ-butyrolactones and 3-substituted epoxy esters. This strategy has been successfully employed in the formal synthesis of biologically active 3,4-disubstituted piperidine derivatives, (-)-paroxetine and Ro 67-8867 and a natural product, (+)-eldanolide.
- Devalankar, Dattatray A.,Karabal, Pratibha U.,Sudalai, Arumugam
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p. 1280 - 1285
(2013/05/08)
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- Lactones 30. Reaction of halolactones with trialkylphosphites
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The reaction of halolactones with trialkylphosphites in the presence of water afforded dehalogenated lactones.
- Pisarski, Bart?omiej,Wawrzeńczyk, Czes?aw
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p. 6875 - 6877
(2007/10/03)
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- Stereocontrolled iodolactonization of acyclic olefinic amides
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Acyclic olefinic amides were iodolactonized in the mixed solvent of CH3CN and H2O (90:10, v/v) under reflux to give products with trans configuration of the newly formed iodomethyl to the inherent alkyl group in high yield.
- Ha,Lee,Park
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p. 3645 - 3650
(2007/10/03)
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- Synthesis of 4-Penten-4-olides (γ-Methylene-γ-butyrolactones) via 4-Pentenoic Acids
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4-Penten-4-olides (γ-Methylene-γ-butyrolactones) 7 are easily accessible starting from allylic alcohols 1, which on ortho ester Claisen rearrangement and hydrolytic work-up furnish 4-pentenoic acids 5.The latter on iodolactonization and hydrogen iodide elimination by means of 1,8-diazabicycloundec-7-ene (DBU) furnish 7, in good over-all yield and with variable substitution patterns. - Iodolactonization under kinetic control shows moderate 1,2- or 1,3-asymmetric induction (3:1 and ca. 2:1, respectively).The composition of the iodolactone mixtures 6 as well as the individual relative configurations are deduced from 1H and 13C NMR data. - Similary, the spirobipentenolide 13 is obtained starting from diethyl diallylmalonate (9) via 11 resulting from ester iodocyclization.
- Guenther, Hans Juergen,Guntrum, Eberhard,Jaeger, Volker
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