683788-64-9

Upstream product

• 1107062-54-3 (2R,3R)-2-allyloxy-1,3-bis(benzyloxy)pent-4-ene 
• 63976-48-7 ethyl 4,6-di-O-acetyl-2,3-dideoxy-α,β-D-threo-hex-2-enopyranoside 
• 55735-69-8 ethyl-(di-O-acetyl-ξ-D_g-threo-2,3-dideoxy-hexopyranoside) 
• 1002099-21-9 C₃₃H₃₄O₄S 
• 1315305-92-0 C₂₉H₃₀O₆S₃ 

Downstream Products

• 1107062-56-5 (2R,3R,6S)-3-(benzyloxy)-2-(benzyloxymethyl)-6-(4-methoxyphenyl)-3,6-dihydro-2H-pyran 
• 1279711-71-5 C₂₀H₂₂O₄ 
• 871695-87-3 (2R,3R,4aS,5S,7R,8S,8aS)-3-Benzyloxy-2-benzyloxymethyl-8-tert-butoxycarbonylamino-4a,5-dihydroxy-octahydro-chromene-7-carboxylic acid ethyl ester 
• 871695-83-9 (2R,3R,7R,8S,8aR)-3-Benzyloxy-2-benzyloxymethyl-8-tert-butoxycarbonylamino-3,4,6,7,8,8a-hexahydro-2H-chromene-7-carboxylic acid ethyl ester 

Relevant academic research and scientific papers

A facile method for the synthesis of fused perhydropyrano[2,3: -b] pyrans promoted by Yb(OTf)3

A stereospecific three-component domino reaction between glycals, alkylidene malonate and aldehydes catalyzed by Yb(OTf)3 is described. Multi-substituted cis-fused perhydropyrano[2,3-b]pyran derivatives were obtained with high diastereoselectiv

Stereoelectronic factors in the stereoselective epoxidation of glycals and 4-deoxypentenosides

Glycals and 4-deoxypentenosides (4-DPs), unsaturated pyranosides with similar structures and reactivity profiles, can exhibit a high degree of stereoselectivity upon epoxidation with dimethyldioxirane (DMDO). In most cases, the glycals and their corresponding 4-DP isosteres share the same facioselectivity, implying that the pyran substituents are largely responsible for the stereodirecting effect. Fully substituted dihydropyrans are subject to a "majority rule", in which the epoxidation is directed toward the face opposite to two of the three groups. Removing one of the substituents has a variable effect on the epoxidation outcome, depending on its position and also on the relative stereochemistry of the remaining two groups. Overall, we observe that the greatest loss in facioselectivity for glycals and 4-DPs is caused by removal of the C3 oxygen, followed by the C5/anomeric substituent, and least of all by the C4/C2 oxygen. DFT calculations based on polarized-π frontier molecular orbital (PPFMO) theory support a stereoelectronic role for the oxygen substituents in 4-DP facioselectivity, but less clearly so in the case of glycals. We conclude that the anomeric oxygen in 4-DPs contributes toward a stereoelectronic bias in facioselectivity whereas the C5 alkoxymethyl in glycals imparts a steric bias, which at times can compete with the stereodirecting effects from the other oxygen substituents.

Synthesis of 3-deoxy glycals via tandem metathesis sequences and their use in an intermolecular heck arylation

Deoxy glycals can be synthesized from a mannitol-derived C 2-symmetric diene diol by using the tandem RCM/isomerization approach. Incorporation of a ruthenium-catalyzed dehydrogenative silylation step into the reaction sequence is possible. Thus, an orthogonally protected 3-deoxy glycal results via a tandem RCM/hydrosilylation/isomerization sequence. All ruthenium-catalyzed steps of this tandem sequence occur under distinct conditions, allowing for the selective synthesis of the intermediates. The 3-deoxy glycals obtained via this route undergo a regio- and stereoselective Heck reaction, as exemplified by the synthesis of a C-aryl glycoside. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.