- The total syntheses of D-erythro-sphingosine, N-palmitoylsphingosine (ceramide), and glucosylceramide (cerebroside) via an azidosphingosine analog
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The total synthesis of D-erythro-sphingosine (9) was performed by a chirospecific method starting from D-galactose via an azidosphingosine intermediate to give highly homogeneous ( > 99.9% C18:1) sphingosine base (9) which contained no observable olefin isomerization by product and was demonstrated to be optically pure by a novel method utilizing Mosher's acid. Ceramide (10) was prepared from this sphingosine (9) with highly homogeneous (99.8% C16:0) palmitic acid by two methods. The cerebroside glucosylceramide (23) was the next sphingolipid in this series to be synthesized in a highly homogeneous form. These three sphingolipids are currently being used for biophysical studies of the structures of their hydrated bio-molecular assemblies.
- Duclos Jr., Richard I
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p. 111 - 138
(2007/10/03)
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- Synthesis of Sphingosines, 4. - Synthesis of erythro-Sphingosines via Their Azido Derivatives
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The 2,4-O-protected D-threoses 3a and 3b were obtained from D-galactose and D-xylose, respectively, in two-step procedures.Wittig reaction in the presence of an excess of lithium bromide afforded the trans-enetriols 4aA, 4aB, and 4bA.Triflate activation of the unprotected 2-hydroxy group, azide group introduction, and cleavage of the O-protective groups yielded the azidosphingosines 6A,B which provide after azide group reduction the D-erythro-sphingosines 7A,B.For the glycosphingolipid synthesis through azidosphingosine glycosylation, compound 6A was transformed by 1-O tritylation, 3-O protection, and subsequent 1-O detritylation into the 3-O-protected azidosphingosines 11α-11γ.
- Zimmermann, Peter,Schmidt, Richard R.
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p. 663 - 668
(2007/10/02)
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