Lithium Perchlorate epoxide opening

Chiral amino alcohols can be prepared by reaction of chiral epoxides with amines. Enantiopure (25, 3.R)-2,3-epoxy-3-phenylpropanol anchored to Merrifield resin has been used for ring-opening with secondary amines in the presence of lithium perchlorate to afford polymer-supported chiral amino alcohols 47 (Eq. 18) [56], By analogy, (2i ,35)-3-(cis-2,6-dimethylpiperidino)-3-phenyl-l,2-propanediol has been anchored to a 2-chlorotrityl chloride resin (48). Although this polymer had high catalytic activity in the enantioselective addition of diethylzinc to aldehydes, the selectivity of the corresponding monomeric catalyst was higher (97 % ee) in the same reaction. 

Epoxide ring opening by water promoted by the lithium perchlorate, followed by dehydration. 

Diphenyl phosphorazidate [DPPA, (Ph0)2P(0)N3l with 4-dimethylaminopyridine (DMAP) and lithium perchlorate opens epoxides regio- and stereo-selectively to yield O-diphenylphosphoryl vicinal azidohydrins see, for example, (15) (16). In the case of O, /3-epoxy ketones and esters, only the corresponding a-azidovinyl ketones and esters were obtained. This is attributed to the acidity of the a-H facilitating dephosphorylation of the initial product. 

Friedel-Craft Alkylation. St)rene epoxides can be opened efficiently at the benzylic position when treated with lithium perchlorate to provide the desired alcohol in 95% yield (eq 5). ... 

An improved synthesis of 3-cyano-3-deoxy- and 3-deoxy-3-formyl-hex-2-eno-pyranosides has been described. Thus treating methyl 2,3-anhydro-4,6-0-benzyl-idene-a-D-galactopyranoside with diethylaluminium cyanide (epoxide ring opening with CN) then elimination of water with diisopropylamine, lithium perchlorate and tosyl chloride afforded 39 which on reduction with DIBAL gave 40.34... 

A library of -amino alcohols was prepared by Ganesan et al. [7] by the lithium perchlorate promoted ring opening of epoxides using small pools of primary and secondary amines. The amines were divided into structural classes and representatives of each class were used in multiple pools of four. Each pool of amines was reacted with 80 epoxides to generate the library of >6000 samples. 

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