56145-21-2

Upstream product

• 13171-64-7 Dimethyl D-tartrate 
• 74-88-4 methyl iodide 
• 186581-53-3 diazomethane 
• 87-69-4 L-Tartaric acid 
• 67-56-1 methanol 
• 114596-70-2 dextrorotatory α.α'-dimethoxy-succinic acid dichloride 
• 7305-62-6 (2R,3R)-2,3-dimethoxysuccinnic acid 
• 2296-47-1 methyl 2,3,4,6-tetra-O-methyl-β-D-galactopyranoside 
• 608-68-4 dimethyl L-tartrate 
• 127319-77-1 dextrorotatory α.α'-dimethoxy-succinic acid monomethyl ester 
• 38411-48-2 (2R,3S)-2,3-Dimethoxy-3-(5,7,10-trimethoxy-3,4-dioxo-3,4-dihydro-anthracen-2-yl)-propionic acid methyl ester 
• 211803-48-4 (2R,3R)-2,3-Dimethoxy-3-((2S,3S,4R,5S)-2,3,4,5-tetrahydroxy-tetrahydro-pyran-2-yl)-propionic acid methyl ester 
• 159299-69-1 (E)-3-((3aS,3bR,7aS,8aS)-2,2,5,5-Tetramethyl-tetrahydro-[1,3]dioxolo[4,5]furo[3,2-d][1,3]dioxin-8a-yl)-acrylic acid methyl ester 
• 211803-45-1 (2R,3R)-2,3-Dihydroxy-3-((3aS,3bR,7aS,8aS)-2,2,5,5-tetramethyl-tetrahydro-[1,3]dioxolo[4,5]furo[3,2-d][1,3]dioxin-8a-yl)-propionic acid methyl ester 

Downstream Products

• 55933-41-0 (+)-(2S,3S)-1,4-Bis(tosyloxy)-2,3-dimethoxybutane 
• 811867-72-8 methyl (3S,4S)-3,4-dimethoxy-1-{[(3S,4S)-3,4-dimethoxy-1-{[(3S,4S)-3,4-dimethoxy-1-{[(3S,4S)-3,4-dimethoxy-1-(benzyloxycarbonylamino)cyclopentyl]carbonylamino}cyclopentyl]carbonylamino}cyclopentyl]carbonylamino}cyclopentanecarboxylate 
• 811867-69-3 (3S,4S)-1-benzyloxycarbonylamino-3,4-(dimethoxy)cyclopentanecarboxylic acid 
• 811867-68-2 methyl (3S,4S)-1-benzyloxycarbonylamino-3,4-(dimethoxy)cyclopentanecarboxylate 
• 289886-42-6 H-(S,S)-Ac₅cdOM-OMe 
• 1380078-04-5 Cbz-[(R,R)-Ac₅c(dOM)]4-OMe 
• 1380078-01-2 (3R,4R)-1-benzyloxycarbonylamino-3,4-(dimethoxy)cyclopentanecarboxylic acid 
• 1380078-00-1 methyl (3R,4R)-1-benzyloxycarbonylamino-3,4-(dimethoxy)cyclopentanecarboxylate 
• 1236286-57-9 H-(R,R)-Ac₅cdOM-OMe 

Relevant academic research and scientific papers

Absolute stereochemistry of chiral, C60 fullerene bis-adducts

To determine the absolute configuration of chiral fullerene bis-adducts, we have studied the double Bingel reaction of C60 with chiral tether (2S,3S)-(-)-9 derived from (R,R)-(+ -tartaric acid, and have succeeded in isolating two possible chiral bis-adducts 10a (5%) and 10b (2%) in addition to the Cs-symmetrically added derivative 10c (40%). The CD spectra of chiral bis-adducts [CD(+)281]-10a and [CD(-)281]-10b show very intense Cotton effects, which are almost of mirror image, indicating that their chiral C60 π-electron systems are enantiomeric each other. The 1H and 13C NMR spectra of 10a and 10b indicate that they have C2-symmetrical structures, and the vicinal coupling constants between two equivalent protons H-2 and H-2′ were determined as 1.2 Hz for 10a and 1.8 Hz for 10b, respectively by the 13C satellite band method. From the conformational analyses, the absolute configurations of these chiral C60 fullerene bis-adducts were unambiguously determined as [CD(+)281]-(S,S,fC)-10a and [CD(-)281]-(S,S,fA) -10b, respectively.

The stereoselective synthesis of novel 4-octulose derivatives

Dihydroxylation of methyl (E)-2,3-dideoxy-4,5:6,8-di-O-isopropylidene- L-xylo-oct-2-ene-4-ulofuranosonate (1) with osmium tetraoxide took place with high diastereoselectivity to give a 7:1 mixture of methyl 4,5:6,8-di-O- isopropylidene-α-L-glycero-D-galacto- (2) and -D-ido-oct-4-ulofuranosonate (3). When 1 was dihydroxylated in the presence of dihydroquinine and dihydroquinidine p-chlorobenzoate, an appreciable increase and decrease, respectively, in the 2/3 ratio was observed. Compound 2 was transformed into its 2,3-di-O-methyl derivative 4 which was deisopropylidenated to methyl 2,3- di-O-methyl-α-L-glycero-D-galacto-oct-4-ulopyranosonate (5) and subsequently degraded to dimethyl 2,3-di-O-methyl-(+)-L-tartrate (6). On the other hand, compounds 2 and 3, separately, were isopropylidenated to the corresponding 2,3:4,5:6,8-tri-O-isopropylidene derivatives 7 and 8, which were reduced with LiAlH4 to the related 2,3:4,5:6,8-tri-Oisopropylidene-α-L-glycero-D- galacto- (9) and -D-ido-oct-4-ulofuranose (10). Finally, compounds 9 and 10 were deisopropylidenated to the corresponding L-glycero-D-galacto- (11) and L-glycero-Dido-oct-4-ulose (12).

Synthesis of 4-octuloses from a derivative of D-fructose

Reaction of 2,3:4,5-di-O-isopropylidene-β-D-arabino-hexos-2-ulo-2,6-pyranose (1) with (methoxycarbonylmethylene)triphenylphosphorane in either dichloromethane or methanol gave methyl (E)-2,3-dideoxy-4,5:6,7-di-O-isopropylidene-β-D-arabino-oct-2-ene-4-ulo-4, 8-pyranosonate (2) or a 1:2.3 mixture of 2 and its Z-isomer (3), respectively. Bishydroxylation of 2 with osmium tetraoxide gave a mixture of methyl 4,5:6,7-di-O-isopropylidene-β-D-glycero-D-galacto-(4) and -D-glycero-D-ido-oct-4-ulo-4,8-pyranosonate (5) which were carefully resolved by column chromatography. Compound 4 was transformed into its 2,3-di-O-methyl derivative (6) which was deacetonated to 7 and subsequently degraded to dimethyl 2,3-di-O-methyl-(+)-L-tartrate (8). On the other hand, acetonation of a mixture of 4 and 5 gave the corresponding tri-O-isopropylidene derivatives (9) and (10). Compounds 4 and 5 were reduced with LiAlH4 to the related 4,5:6,7-di-O-isopropylidene-β-D-glycero-D-galacto-(11) and -β-D-glycero-D-ido-oct-4-ulo-4,8-pyranose (12). Treatment of 11 and 12 with acetone/PTSA/CuSO4 only produced the acetonation at the C-2,3 positions. Finally, compounds 11 and 12 were deacetonated to the corresponding D-glycero-D-galacto-(15) and D-glycero-D-ido-oct-4-ulose (16).

One-handed helical screw direction of homopeptide foldamer exclusively induced by cyclic α-amino acid side-chain chiral centers

Chiral cyclic α,α-disubstituted amino acids, (3S,4S)- and (3R,4R)-1-amino-3,4-(dialkoxy)cyclopentanecarboxylic acids ((S,S)- and (R,R)-Ac5cdOR; R: methyl, methoxymethyl), were synthesized from dimethyl L-(+)- or D-(-)-tartrate, and their homochiral homoligomers were prepared by solution-phase methods. The preferred secondary structure of the (S,S)-Ac5cdOMe hexapeptide was a left-handed (M) 3 10 helix, whereas those of the (S,S)-Ac5cdOMe octa- and decapeptides were left-handed (M) α helices, both in solution and in the crystal state. The octa- and decapeptides can be well dissolved in pure water and are more α helical in water than in 2,2,2-trifluoroethanol solution. The left-handed (M) helices of the (S,S)-Ac5c dOMe homochiral homopeptides were exclusively controlled by the side-chain chiral centers, because the cyclic amino acid (S,S)-Ac 5cdOMe does not have an α-carbon chiral center but has side-chain γ-carbon chiral centers. Copyright