Synthesis of 4-alkyl-pyrrolidine-3-carboxylic acid stereoisomers
摘要:
All four possible stereoisomers of the 3-carboxyl-4-isopropyl-pyrrolidine (4) were prepared and their stereochemistry was assigned unambiguously. (C) 2001 Elsevier Science Ltd. All rights reserved.
DOI:
10.1016/s0040-4020(01)00549-x
作为产物:
描述:
5-methyl-hex-2-ynoic acid ethyl ester 在
Pd barium sulfate silica gel 、 乙炔 、 olefin 、 乙醚 、 pet ether 作用下,
以
四氢呋喃 、 吡啶 为溶剂,
反应 3.25h,
以to give pure fractions of (Z)-5-methyl-hex-2-enoic acid ethyl ester 8 (12.0 g)的产率得到5-甲基-2-己烯酸乙酯
rhodium(I) by means of an RhI–OH complex, enables the conjugate transfer of nucleophilic silicon onto α,β-unsaturated acceptors. Pre- or in situ formed cationic rhodium(I)–binap complexescatalyze this novel carbon–silicon bond formation with exceptional enantiocontrol, 92 to >99% ee for cyclic carbonyl and carboxylcompounds as well as >99% ee for acyclic carboxylcompounds.
铑(I)催化的硅-硼键活化,即通过Rh I -OH络合物将硅从硼转变为铑(I),可以将亲核硅共轭转移到α,β上-不饱和受体。预制的或原位形成的阳离子铑(I)-联萘酚配合物可催化这种新型的碳-硅键形成,具有出色的对映体控制能力,环状羰基和羧基化合物的ee为92%至> 99%ee,无环羧基化合物的ee> 99%。
N-acyl-5,5-dimethyl-oxazolidin-2-ones as latent aldehyde equivalents
作者:Jordi Bach、Steven D. Bull、Stephen G. Davies、Rebecca L. Nicholson、Hitesh J. Sanganee、Andrew D. Smith
DOI:10.1016/s0040-4039(99)01345-3
日期:1999.9
N-acyl-5,5-dimethyl-oxazolidin-2-ones can function as versatile latent aldehyde equivalents - reductive cleavage with DIBAL-H affords aldehydes in good yield, while tandem DIBAL-H/Wittig methodology affords α,β-unsaturatedesters.
Practical Synthesis of (E)-α,β-Unsaturated Esters from Aldehydes
作者:Benjamin List、Arno Doehring、Maria T. Hechavarria Fonseca、Kathrin Wobser、Hendrik van Thienen、Ramon Rios Torres、Pedro Llamas Galilea
DOI:10.1002/adsc.200505196
日期:2005.10
Based on a modification of the Doebner–Knoevenagel reaction, a practical and highly efficient synthesis of α,β-unsaturated esters with excellent regio- and stereoselectivity was developed. The reactions are catalyzed by 4-dimethylaminopyridine in DMF at room temperature or below. Both aliphatic and aromatic aldehydes can readily be used in the process.
Practical synthesis of Z-unsaturated esters by using a new Horner-Emmons reagent, ethyl diphenylphosphonoacetate
作者:Kaori Ando
DOI:10.1016/0040-4039(95)00726-s
日期:1995.6
A new Horner-Emmons reagent, ethyl diphenylphosphonoacetate 1 was prepared from triethylphosphonoacetate, PCl5, and phenol in 60% overall yield. Horner-Emmons reactions of 1 with aldehydes in the presence of Triton® B or NaH in THF gave the Z-unsaturated esters in 89–93% selectivity in almost quantitative yields. Furthermore, 1 showed up to 99% Z-selectivity under Still's condition (KHMDS/18-crown-6)
Branched alkyl pyrrolidines of formula (I) are disclosed and are useful as agents in the treatment of epilepsy, faintness attacks, hypokinesia, cranial disorders, neurodegenerative disorders, depression, anxiety, panic, pain, and neuropatnological disorders. Processes for the preparation and intermediates useful in the preparation are also disclosed.