358972-66-4

Upstream product

• 106-95-6 allyl bromide 
• 100-46-9 benzylamine 
• 175844-96-9 2,3,4-Tri-O-benzyl-5,6-dideoxy-L-arabino-hex-5-enose 
• 305834-18-8 (2S,3R,4S,5R)-3,4,5-tris(benzyloxy)-2-(iodomethyl)-6-methoxytetrahydro-2H-pyran 

Downstream Products

• 358972-69-7 (2R,3R,4S,5R)-5-[N-benzyl-N-(benzyloxycarbonyl)amino]-2,3,4-tris(benzyloxy)cycloheptanone 
• 358972-68-6 (3S,4S,5S,6R)-6-[N-benzyl-N-(benzyloxycarbonyl)amino]-3,4,5-tris(benzyloxy)cycloheptene 
• 358972-67-5 (3S,4S,5S,6R)-6-[N-benzyl-N-(benzyloxycarbonyl)amino]-3,4,5-tris(benzyloxy)-1,8-nonadiene 

Relevant academic research and scientific papers

Short syntheses of enantiopure calystegine B2, B3, and B4

Calystegine B2, B3, and B4 have been prepared in 5 steps from the benzyl protected methyl 6-iodoglycopyranosides of glucose, galactose and mannose, respectively, by using a zinc-mediated domino reaction followed by ring-cl

A short synthetic route to the calystegine alkaloids

An efficient strategy is described for the synthesis of enantiopure calystegine alkaloids. The key step employs a zinc-mediated fragmentation of benzyl-protected methyl 6-iodo-glycosides followed by in situ formation of the benzyl imine and Barbier-type allylation with zinc, magnesium, or indium metal. Stereochemistry in the pivotal allylation is controlled by the choice of the metal. The functionalized 1,8-nonadienes, thus formed, are converted into cycloheptenes by ring-closing olefin metathesis. Regioselective hydroboration and oxidation give the corresponding cycloheptanones, which are deprotected to afford the desired calystegines. Hereby, calystegine B2, B3, and B4 are prepared from D-glucose, D-galactose, and D-mannose, respectively. This route constitutes the shortest synthesis of calystegine B2 and gives rise to the first total syntheses of calystegine B3 and B4.