Diastereoselective electrophilic substitution of γ-oxy-substituted benzyllithiums
摘要:
Reductive lithiation of diastereoisomeric mixtures of 4-aryl-5-methyl-1,3-dioxanes occurs with epimerization at the benzylic centre. Reaction of intermediate organometals with alkyl halides or CO2 afforded 2-methyl-3-substituted-3-phenylpropan-1-ols, or the corresponding lactones, with satisfactory yields and satisfactory to high diastereoselectivities. Observed diastereoselectivities strongly depend on the substitution pattern of starting materials. (C) 2002 Elsevier Science Ltd. All rights reserved.
An improved synthesis of a polymer-supported distannane and its application to radical formation
作者:Jörg Junggebauer、Wilhelm P Neumann
DOI:10.1016/s0040-4020(96)01078-2
日期:1997.1
A polymer-supported distannane 1 was prepared by treatment of tin halide resin with lithium naphthalenide or sodiumnaphthalenide in THF. The content of the polymers 1 was determined to be 0.95 to 1.13 mmol/g tin as ditin. The polymer-supported distannane reagent was successfully applied to radical cyclizations of acyclic α-haloesters to yield γ-butyrolactones.
The present invention is directed to certain phenyl pyrrolidine ether compounds which are useful as neurokinin-1 (NK-1) receptor antagonists, and inhibitors of tachykinin and in particular substance P. The invention is also concerned with pharmaceutical formulations comprising these compounds as active ingredients and the use of the compounds and their formulations in the treatment of certain disorders, including emesis, depression, and anxiety.
Diastereoselective electrophilic substitution of γ-oxy-substituted benzyllithiums
作者:Maria A Arrica、Ugo Azzena、Luciano Pilo、Elisabetta Piras
DOI:10.1016/s0040-4039(02)00989-9
日期:2002.7
Reductive lithiation of diastereoisomeric mixtures of 4-aryl-5-methyl-1,3-dioxanes occurs with epimerization at the benzylic centre. Reaction of intermediate organometals with alkyl halides or CO2 afforded 2-methyl-3-substituted-3-phenylpropan-1-ols, or the corresponding lactones, with satisfactory yields and satisfactory to high diastereoselectivities. Observed diastereoselectivities strongly depend on the substitution pattern of starting materials. (C) 2002 Elsevier Science Ltd. All rights reserved.