503065-75-6

Upstream product

• 3615-41-6 L-Rhamnose 
• 108-98-5 thiophenol 
• 930-69-8 sodium thiophenolate 
• 153745-67-6 phenyl 2,3,4-tri-O-acetyl-1-thio-β-L-rhamnopyranoside 
• 5158-64-5 2,3,4-tri-O-acetyl-α-L-rhamnopyranosyl bromide 
• 73-34-7 L-rhamnose 
• 181136-65-2 phenyl 2,3,4-tri-O-acetyl-1-thio-6-deoxy-β-L-mannopyranoside 

Downstream Products

• 181136-65-2 phenyl 2,3,4-tri-O-acetyl-1-thio-6-deoxy-β-L-mannopyranoside 
• 1382228-97-8 phenyl 3,4-di-O-(2,3-dimethoxybutane-2,3-diyl)-1-thio-β-L-rhamnopyranoside 
• 1382229-04-0 C₁₉H₂₂O₆S₂ 
• 1382229-08-4 phenyl 2-O-sulfonylbenzyl-4-O-TIPS-1-thio-β-L-rhamnopyranoside 
• 1382229-12-0 phenyl 2-O-sulfonylbenzyl-3,4-di-O-TIPS-1-thio-β-L-rhamnopyranoside 
• 1382229-16-4 phenyl 2-O-sulfonylbenzyl-3-O-TBS-4-O-TIPS-1-thio-β-L-rhamnopyranoside 
• 1382229-20-0 phenyl 2-O-sulfonylbenzyl-4-O-TIPS-3-O-TMS-1-thio-β-L-rhamnopyranoside 
• 1382230-17-2 C₃₄H₆₂O₇SSi₂ 
• 1382230-20-7 C₃₄H₆₂O₇SSi₂ 
• 1382230-29-6 C₅₆H₈₂O₁₂SSi₂ 
• 1382230-32-1 C₃₁H₅₆O₇SSi₂ 
• 1382230-35-4 C₃₁H₅₆O₇SSi₂ 
• 1382230-38-7 C₂₈H₄₈O₇SSi 
• 1382230-41-2 C₂₈H₄₈O₇SSi 

Relevant academic research and scientific papers

Synthesis of Cardiotonic Steroids Oleandrigenin and Rhodexin B

This article describes a concise synthesis of cardiotonic steroids oleandrigenin (7) and its subsequent elaboration into the natural product rhodexin B (2) from the readily available intermediate (8) that could be derived from the commercially available steroids testosterone or DHEA via three-step sequences. These studies feature an expedient installation of the β16-oxidation based on β14-hydroxyl-directed epoxidation and subsequent epoxide rearrangement. The following singlet oxygen oxidation of the C17 furan moiety provides access to oleandrigenin (7) in 12 steps (LLS) and a 3.1% overall yield from 8. The synthetic oleandrigenin (7) was successfully glycosylated with l-rhamnopyranoside-based donor 28 using a Pd(II)-catalyst, and the subsequent deprotection under acidic conditions provided cytotoxic natural product rhodexin B (2) in a 66% yield (two steps).

Rhamnosylation: Diastereoselectivity of conformationally armed donors

The α/β-selectivity of super-armed rhamnosyl donors have been investigated in glycosylation reactions. The solvent was found to have a minor influence, whereas temperature was crucial for the diastereoselectivity. At very low temperature, a modest β-selectivity could be obtained, and increasing temperature gave excellent α-selectivity. The donors were highly reactive, and activation was observed at temperatures as low as -107 °C. Different promoter systems and leaving groups were investigated, and only activation with a heterogeneous catalyst increased the amount of the β-anomer significantly. By introducing an electron-withdrawing nonparticipating group, benzyl sulfonyl, on 2-O, an increase in β-product was observed.

Conformational analysis of sulfur-containing 6-deoxy-L-hexose derivatives by molecular modeling and NMR spectroscopy. A theoretical study and experimental evidence of intramolecular nonbonded interactions between sulfur and oxygen

6-Deoxy-L-mannose diphenyldithioacetal (1) unexpectedly gave the rearranged products phenyl 3,4-di-O-acetyl-2-S-phenyl-1,2-dithio-6-deoxy-β -L-glucopyranoside (9) and 3,4-di-O-acetyl-2,5-anhydro-6-deoxy-L-glucose diphenyldithioacetal (10) upon treatment w

Direct synthesis of the beta-l-rhamnopyranosides.

The direct formation of beta-l-rhamnopyranosides by means of thioglycoside donors protected with a 2-O-sulfonate ester and, ideally, a 4-O-benzoyl ester, is reported. Activation is achieved with the combination of 1-benzenesulfinyl piperidine and triflic anhydride in the presence of 2,4,6-tri-tert-butylpyrimidine. Selectivities vary from moderate to good, and the sulfonyl group is easily removed post-glycosylation with sodium amalgam in 2-propanol.

Synthesis of Lewis X trisaccharide analogues in which glucose and rhamnose replace N-acetylglucosamine and fucose, respectively

Two analogues of the Lex trisaccharide, α-L-Fucp-(1→3)-[β-D-Galp-(1→4)]-D-Glcp were synthesized as allyl glycosides. In these derivatives either only the N-acetylglucosamine is replaced by glucose or both the N-acetylglucosamine and the fucosyl residue are replaced by glucose and rhamnose, respectively. Our synthetic scheme used armed β-thiophenyl fuco- and rhamnoside glycosyl donors that were prepared anomerically pure from the corresponding α-glycosyl bromides. The protecting groups were chosen to allow access to the fully deprotected trisaccharides without reduction of the allyl glycosidic group. These analogues will be used as soluble antigens in binding experiments with anti-Lex antibodies and can also be conjugated to a carrier protein and used as immunogens. In the course of this synthetic work, we also describe the use of reversed-phase HPLC to purify key protected trisaccharide intermediates prior to their deprotection.