- Stereochemistry of an Allyl Cyanate-to-isocyanate Rearrangement
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The stereochemistry of an allyl cyanate-to-isocyanate rearrangement has been investigated by employing a chiral allyl carbamate.The rearrangement has been found to be stereospecific and the chirality of an allyl cyanate is transformed into that of an ally
- Ichikawa, Yoshiyasu,Tsuboi, Katsunori,Isobe, Minoru
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p. 2791 - 2796
(2007/10/02)
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- Synthesis of Chiral Vinylglycines
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(R)- or (S)-benzyl 4-formyl-2,2-dimethyl-3-oxazolidinecarboxylate (7a) and (R)- or (S)-1,1-dimethylethyl 4-formyl-2,2-dimethyl-3-oxazolidinecarboxylate (7b), readily available from serine, react with Wittig reagents to give alkenes 8.Selective deprotection followed by oxidation of the resulting unsaturated amino alcohols 9 provides vinylglycines 5 of defined configuration (>95percent ee) and double-bond geometry.D-Vinylglycines are obtained from L-serine, and conversely, D-serine gives β,γ-unsaturated amino acids with the L configuration.The double-bond geometry is controlled by the nature of the phosphorous ylide employed.The scope and limitations of this new methodology for the preparation of chiral vinylglycines is examined.
- Beaulieu, Pierre L.,Duceppe, Jean-Simon,Johnson, Carolyne
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p. 4196 - 4204
(2007/10/02)
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