Treatment of N-Boc Derivatives of β-Amino Alcohols with N,N-Diethylaminosulfur Trifluoride Leads to Chiral Oxazolidinones: An Unexpected Intramolecular Cyclization
Pinacol Cross Coupling of 2-[N-(Alkoxycarbonyl)amino] Aldehydes and Aliphatic Aldehydes by [V2Cl3(THF)6]2[Zn2Cl6]. Synthesis of syn,syn-3-[N-(Alkoxycarbonyl)amino] 1,2-Diols
作者:Andrei W. Konradi、Scott J. Kemp、Steven F. Pedersen
DOI:10.1021/ja00083a017
日期:1994.2
Slow addition of 2-[N-(alkoxycarbonyl)amino] aldehydes to mixtures of [V 2 Cl 3 (THF) 6 ] 2 [Zn 2 Cl 6 ] and aliphaticaldehydes gave syn,syn-3-[N-(alkoxycarbonyl)amino] 1,2-diols in good yield and high enantiomeric purity (>99:1). The alkyl group of the N-alkoxycarbonyl was shown to influence the yield: Me >allyl>Bn>t-Bu. Only the syn,syn diastereomer was observed (>20:1), except with N-Cbz-alaninal
the respective homochiral α-amino alcohols. The absolute configuration at the created stereogenic centre was assigned by CD spectra and by X-rayanalysis. Conformational analysis of the title compounds was carried out using quantum chemical energy-geometry optimization. Thus established conformational behavior explained the strongly configuration dependent NMR spectral patterns observed for the u and
Amino groups are selectively protected in good yields by reaction with O-alkyl S-(pyridin-2-yl)carbonothiolates in an appropriate solvent at room temperature in air. Even glucosamine, which contains multiple hydroxyl groups, is selectively N-protected in methanol.
通过与 O-烷基 S-(吡啶-2-基)碳硫醇盐在适当的溶剂中在室温下在空气中反应,氨基以良好的产率被选择性地保护。甚至含有多个羟基的葡糖胺也在甲醇中被选择性地 N 保护。
Treatment of <i>N</i>-Boc Derivatives of β-Amino Alcohols with <i>N</i>,<i>N</i>-Diethylaminosulfur Trifluoride Leads to Chiral Oxazolidinones: An Unexpected Intramolecular Cyclization