Role of the Heteroatoms in the Complex Metal Hydride Reduction of 2-<i>t</i>-Butyl-1,3-dioxan-5-one and 3-Oxoquinolizidine: Comparison of Their Reactivity and Stereochemistry with Those of the Corresponding Carbocyclic Compounds
作者:Yasuhisa Senda、Hiroshi Sakurai、Hiroki Itoh
DOI:10.1246/bcsj.72.285
日期:1999.2
The complexmetalhydridereductions of 2-t-butyl-1,3-dioxan-5-one (1) and 3-oxoquinolizidine (3) are faster than those of the corresponding carbocyclic compounds, 4-t-butylcyclohexanone (2) and trans-2-decalone (4). The stereoselectivities were similar in the LiAlH4 reduction, but the heteracyclohexanones exhibited higher stereoselectivity with NaBH4. These facts are discussed in terms of the intramolecular
was observed in the latter two compounds regardless of the catalyst metals used here. These results were explained in terms of intramolecular nO–πCO interaction, which was supported by 13C NMR chemical shifts of the carbonyl carbons and CNDO/2calculation.
The enantioselective Horner-Wadsworth-Emmons reaction of 2-fluoro-2-dietliylphosphonoacetates with sigma-symmetric prochiral 2-substituted-1,3-dioxan-5-ones and 4-substituted-cyclohexanones was investigated by employing Sn(OSO2CF3)(2) and N-ethylpiperidine in the presence of an external chiral ligand, (S)-(-)-1-methyl-2-(1-piperidinomethyl)pyrrolidine. A chiral alpha-fluoro-alpha,beta-unsaturated ester was obtained in up to 80% ce. (C) 2002 Elsevier Science Ltd. All rights reserved.
Stereoselective Synthesis of Substituted 5-Hydroxy-1,3-dioxanes
作者:David C. Forbes、Doina G. Ene、Michael P. Doyle
DOI:10.1055/s-1998-2090
日期:1998.6
Majewski, Marek; Gleave, D. Mark; Nowak, Pawel, Canadian Journal of Chemistry, 1995, vol. 73, # 10, p. 1616 - 1626