24923-81-7

Upstream product

• 1666-13-3 diphenyl diselenide 
• 266683-57-2 2-benzyloxy-3-bromotetrahydropyran 
• 100-51-6 benzyl alcohol 
• 110-87-2 3,4-dihydro-2H-pyran 
• 1927-62-4 tetrahydro-2-(benzyloxy)-2H-pyran 

Downstream Products

• 89017-10-7 benzyl 2-O-n-butyl-3-(tert-butylthio)-3,4-dideoxy-α-DL-threo-pentopyranoside 
• 89017-09-4 benzyl 3-(tert-butylthio)-3,4-dideoxy-α-DL-threo-pentopyranoside 
• 124502-72-3 2-(benzyloxy)tetrahydro-2H-pyran-3-ol 
• 541520-85-8 2-benzyloxy-tetrahydro-2H-pyran-3,4-diol 
• 24915-72-8 benzyl 2,3-anhydro-4-deoxy-β-DL-erythro-pento-pyranoside 
• 89064-41-5 benzyl 2,3-anhydro-4-deoxy-α-DL-erythro-pentopyranoside 

Relevant academic research and scientific papers

Backbone-Modified C2-Symmetrical Chiral Bisphosphine TMS-QuinoxP*: Asymmetric Borylation of Racemic Allyl Electrophiles

A new C2-symmetrical P-chirogenic bisphosphine ligand with silyl substituents on the ligand backbone, (R,R)-5,8-TMS-QuinoxP*, has been developed. This ligand showed higher reactivity and enantioselectivity for the direct enantioconvergent borylation of cy

Synthesis of mono- and dihydroxylated furanoses, pyranoses, and an oxepanose for the preparation of natural product analogue libraries

Numerous biologically active natural products contain furanoses and pyranoses with mono- and dihydroxylated substituents. However, much of the structure-activity studies on such molecules is gathered on the aglycons without attention to the corresponding carbohydrate components. Consequently, there are few synthetic procedures that enable the rapid preparation of mono- and dihydroxyfuranoses and mono- and dihydroxypyranoses and no report for a 3,4-dihydroxyoxepanose. In this article we report the practical synthesis of orthogonally protected five-, six-, and seven-membered carbohydrate derivatives. The succinct manner in which these molecules were synthesized allows the rapid preparation of analogues aimed at discovering the role of ring size and individual hydroxyl moieties on the pyranose skeleton.

Novel Preparation of α,β-Unsaturated Aldehydes. Benzeneselenolate Promotes Elimination of HBr from α-Bromoacetals

Acetalization, α-bromination, nucleophilic phenylselenenylation, oxidative elimination/hydrolysis was investigated as a novel protocol for the α,β-dehydrogenation of aldehydes. Treatment of acetals with bromine in methylene chloride afforded the corresponding α-bromoacetals in 80-90% yields. Nucleophilic phenylselenenylation was then conveniently effected by treatment with benzenese-lenolate generated in situ in dimethyl sulfoxide from diphenyl diselenide, hydrazine and potassium carbonate. Unbranched α-bromoacetals cleanly afforded substitution products whereas β- and γ-branched ones gave substantial amounts of α,β-unsaturated acetals via formal loss of hydrogen bromide. Oxidative elimination/hydrolysis of these mixtures afforded α,β-unsaturated aldehydes in 50-80% overall yields. In the case of tertiary α-bromoacetals, treatment with benzeneselenolate afforded only dehydrobromination products as mixtures of isomers. The presence of at least a catalytic amount of the organoselenium reagent was found to be crucial for olefin formation. A SET-mechanism, involving benzeneselenolate-induced electron transfer to the halide, loss of bromide ion, and hydrogen atom or proton/electron was proposed for the benzenselenolate-promoted elimination reaction. Experiments designed to trap carbon-centered radicals in intramolecular cyclization or ring-opening reactions failed to provide any evidence for free-radical intermediates.

Regiochemical control of the ring opening of 1,2-epoxides by means of chelating processes. 8. Synthesis and ring opening reactions of cis- and trans-oxides derived from 3-benzyloxycyclohexene and 2-benzyloxy-5,6-dihydro-2H-pyran

The regiochemical outcome of the ring opening of 1,2-epoxides bearing polar remote functionalization through chelation processes assisted by metal ions, was verified in cyclic oxirane systems having the polar functionality in an allylic position to the oxirane ring. The diastereoisomeric cis/trans epoxide pairs 5,6 and 7,8 derived from 3-benzyloxycyclohexene, and 2-benzyloxy-5,6-dihydro-2H-pyran, respectively, were prepared and several of their opening reactions were studied. The regioselectivity observed largely depends on the reaction conditions (standard or metal-assisted) and, interestingly, on the nature of the nucleophile used.