4233-09-4

Upstream product

• 100-52-7 benzaldehyde 
• 1825-14-5 pentane-1,3-diol 
• 1439-07-2 trans-Stilbene oxide 
• 6296-95-3 1,1,2-triphenyl-1,2-ethanediol 
• 579-43-1 (1S,2R)-1,2-diphenylethane-1,2-diol 
• 1535215-96-3 2-trimethylsilyl-2-phenyl-4,6-dimethyl-1,3-dioxane 

Downstream Products

• 139224-56-9 (±)-4-benzyloxypentan-2-one 
• 101-81-5 Diphenylmethane 
• 137694-24-7 rel-(2R,4R,6S)-2-n-hexyl-4,6-dimethyl-1,3-dioxane 
• 136237-99-5 (2S,4R)-4-((S)-1-Phenyl-but-3-enyloxy)-pentan-2-ol 
• 136237-99-5 (2R,4S)-4-((S)-1-Phenyl-but-3-enyloxy)-pentan-2-ol 
• 3950-21-8 (2R,4S)-2,4-pentanediol 

Relevant academic research and scientific papers

Intramolecular OH...Fluorine Hydrogen Bonding in Saturated, Acyclic Fluorohydrins: The γ-Fluoropropanol Motif

Fluorination is commonly exercised in compound property optimization. However, the influence of fluorination on hydrogen-bond (HB) properties of adjacent functional groups, as well as the HB-accepting capacity of fluorine itself, is still not completely understood. Although the formation of OH...F intramolecular HBs (IMHBs) has been established for conformationally restricted fluorohydrins, such interaction in flexible compounds remained questionable. Herein is demonstrated for the first time - and in contrast to earlier reports - the occurrence of OH...F IMHBs in acyclic saturated γ-fluorohydrins, even for the parent 3-fluoropropan-1-ol. The relative stereochemistry is shown to have a crucial influence on the corresponding h1JOH...F values, as illustrated by syn- and anti-4-fluoropentan-2-ol (6.6 and 1.9 Hz). The magnitude of OH...F IMHBs and their strong dependence on the overall molecular conformational profile, fluorination motif, and alkyl substitution level, is rationalized by quantum chemical calculations. For a given alkyl chain, the "rule of shielding" applies to OH...F IMHB energies. Surprisingly, the predicted OH...F IMHB energies are only moderately weaker than these of the corresponding OH...OMe. These results provide new insights of the impact of fluorination of aliphatic alcohols, with attractive perspectives for rational drug design.

Fluoride-induced proto- and carbo-desilylation of S,S-, O,O- and O,S-silylated acetals: an insight into the chemical and stereochemical reaction outcome

A general overview on the chemical and stereochemical behavior of a wide range of stereodefined 2-silyl-1,3-dithianes, -1,3-dioxanes, -1,3-dioxolanes and -1,3-oxathiolanes is reported, when subjected to fluoride ion-induced proto- and carbo-desilylation. Retention of configuration or epimerization appears to depend not only on the kind of the substituents on the aromatic ring, but also on the nature of heteroatoms in the silyl acetals, leading to envisage the occurence of a free carbanion or of an hypervalent-silylated species.

Chemoselective conversion of aromatic epoxide and 1,2-diol to 1,3-dioxane derivatives with phenyltrimethylammonium tribromide in the presence of a catalytic amount of antimony(III) bromide

trans-Stilbene oxide was oxidatively converted to 2-phenyl-1,3-dioxanes with phenyltrimethylammonium tribromide in the presence of various 1,3-diols and a catalytic amount of SbBr3 in DMSO at room temperature. Aromatic 1,2-diol, such as hydrobenzoin, was similarly converted to 2-aryl-1,3-dioxane derivatives under the same reaction conditions.

Studies on the Mechanism and Origin of Stereoselective Opening of Chiral Dioxane Acetals

A systematic examination of the mechanism and origin of stereoselection in the reaction of dioxane acetals with allyltrimethylsilane was undertaken. Experimental tests for two limiting mechanisms, synchronous (SN-like) and dissociative (SN 1 -like) substitution processes, were investigated. The meso 2,4,6-trisubstituted 1,3-dioxane acetals cis- and trans-1 provided an interesting opportunity to test the timing of bond breaking and making in the substitution reaction. The modest and C(2)-substituent-dependent selectivity excluded the possibility of a direct SN2-type attack on a complexed acetal. Further, the enol ethers 3 and 5 and acyclic acetal 7 were studied as precursors of the putative oxocarbenium ion intermediate in the dissociative limit. The weak and inverted selectivity observed with these substrates ruled out the intermediacy of the extended, separated ion in reactions of the cyclic acetals under similar conditions. A unified mechanistic scheme involving three distinct ion pairs is proposed to explain the dependence of allylation selectivity on structural and experimental variables. The three species are analogous to those proposed in the classic Winstein scheme: (1) an intimate ion pair, (2) an external ion pair, and (3) a separated ion. Each of these proposed intermediates has a different stereochemical profile and the ultimate outcome is a composite of those factors that balance the contribution of the different intermediates. The influence of C(2) substituent, acetal configuration, Lewis acid type and stoichiometry, allylsilane stoichiometry, concentration, solvent, and temperature were investigated and integrated in the proposed mechanistic scheme.