- Asymmetric addition to chiral aromatic and unsaturated oxazolines using a novel chiral auxillary
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By utilizing S-serine, both enantiomers of the reduced methoxyamino alcohol (12) were efficiently prepared. The corresponding oxazolines, prepared from these auxiliaries, showed favorable properties toward additions to naphthalenes 22 and cyclohexene, 27.
- Meyers,Schmidt,McKennon
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p. 250 - 262
(2007/10/02)
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- DIASTEREOSELECTIVE AND ENANTIOSELECTIVE SYNTHESIS OF 1,2-DISUBSTITUTED CYCLOALKANECARBOXALDEHYDES
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A highly useful method for diastereoselective and enantioselective synthesis of trans- and cis-1,2-disubstituted cycloalkanecarboxaldehydes (trans- and cis-10), useful chiral synthons having asymmetric tertiary and quaternary carbon atoms in vicinal positions in their rings, is devised starting from cycloalkenecarboxaldehydes (5). t-Leucine t-butyl ester (2.R=But), a highly effective chiral auxiliary reagent in the present method, can be recovered for recycling without any loss of optical purity.Some mechanistic explanations on the strereochemical courses of the reactions are presented.
- Kogen, Hiroshi,Tomioka, Kiyoshi,Hashimoto, Shun-ichi,Koga, Kenji
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p. 3951 - 3956
(2007/10/02)
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- ASYMMETRIC SYNTHESIS OF 1,2-DISUBSTITUTED CYCLOALKANECARBOXALDEHYDES. PROCEDURES FOR THE HIGHLY STEREOSELECTIVE PREPARATION OF cis- AND trans-ISOMER
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Procedures for the asymmetric synthesis of 1,2-disubstituted cycloalkanecarboxaldehydes (7) having asymmetric tertiary and quaternary carbon atoms in vicinal positions from the corresponding cycloalkenecarboxaldehydes (2) in high diastereomeric and enanti
- Kogen, Hiroshi,Tomioka, Kiyoshi,Hashimoto, Shun-ichi,Koga, Kenji
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p. 4005 - 4008
(2007/10/02)
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