A synthesis of phytosphingosines from D-glucosamine

Abstract

D -rib0 -2 -Be nza mid o -1 ,3,4t r i hydro xy o c ta d e c a n e (Nbe nzo y I -C 1 8p h y to s p h i n g o s i n e) a n d D -rib0 -2be n za mi do -1.3.4-trihydroxyeicosane (N-benzoyl-C20-phytosphingosine) have been synthesised by Wittig reactions between the aldehyde (IX) derived from 2-amino-2-deoxy-13-glucose and the appropriate long-chain phosphoranes. The properties of the derivatives of the synthetic C18-phytosphingosine are identical with those of the corresponding derivatives of the natural base, thus confirming the structure established by previous degradative studies.IN 1911, Zellner described the isolation of a nitrogencontaining substance (" fungus cerebrin ") from the mushroom Amanita muscaria, and later similar materials 2-5 were isolated from other mushrooms, yeasts, and moulds. Reindel and his co-workers3 and Bohonos and Peterson 4 concluded that yeast cerebrin was an amide formed from 4-amino-l,3,5-trihydroxyeicosane (" cerebrin base ") and a fatty acid, and it was shown that cerebrin base gave a crystalline N-benzoyl derivative and a crystalline derivative (" acetone compound 'I), containing acetone, when recrystallised from this solvent. However, Oda reinvestigated the structure of cerebrin base and concluded that it was 2-amino-lJ3,4-trihydroxyoctadecane. Carter and his co-workers reported the presence of a base, with the same structure as that proposed by Oda, in the lipids of plant seeds, and this base gave an "acetone compound" and an N-benzoyl derivative with properties similar to those reported for the corresponding derivatives of cerebrin 1

New Cerebrosides from a Marine Sponge Haliclona (Reniera) sp.

“…25) c) Synthetic product. 26) Animal Material The sponge, Haliclona (Reniera) sp., was collected off the coast of Ulleung Island, Korea in October, 2001, using SCUBA (20 m depth). The collected sample was frozen immediately.…”

Stereoselective synthesis of 1,1′-linked α-l-lyxopyranosyl β-d-glucopyranoside, the proposed biosynthetic precursor of the FG ring system of avilamycins

“…Then 1,2,3,4-tetra-O-acetyl-a/b-L L-lyxopyranose 11 44 (3.5 g, 11 mmol), which had been prepared from L L-lyxose 10 by treatment with Ac 2 O and pyridine according to a published procedure, 52 was added and the mixture was stirred for 16 h at room temperature. After addition of water (50 mL) the precipitate dissolved completely.…”

Convergent Synthesis, NMR and Conformational Analysis of Tetra- and Pentasaccharide Haptens of the Shigella flexneri Serotype 5a O-Specific Polysaccharide

“…[19,20,23] Benzylation of 18 gave 19 (81%), which was de-O-allylated to yield the hemiacetal 20 (82%) by a twostep process involving iridium()-catalysed isomerisation [24] of the allyl glycoside to the prop-1-enyl glycoside and subsequent hydrolysis. [25,26] The selected trichloroacetimidate anomeric leaving group was introduced by treatment of 20 with trichloroacetonitrile in the presence of DBU, which resulted in the formation of 9 (85%). TMSOTf-mediated glycosylation of 9 with 7 resulted in the isolation of disaccharide 21, slightly contaminated with the β anomer 22 (α/ β ഠ 9:1, 93%).…”