Tertiary Amine Promoted Asymmetric Aldol Reaction of Aldehydes
作者:Bartosz Gut、Jacek Mlynarski
DOI:10.1002/ejoc.201500519
日期:2015.8
direct asymmetric self-aldol reactions of various α-oxyaldehydes catalyzed by tertiaryamines have been demonstrated. By using 10 mol-% of quinine catalyst, dimerization products have been prepared in high yields, with good anti-diastereocontrol, and up to 80 % ee. The presented enolate-mediated synthesis of protected tetrose sugars has never been accomplished before by chiral tertiaryamine organocatalysts
Highlysyn-selective cross-aldol reaction of aldehydes has remained a challenging subject in the field of aminocatalysis. To achieve this end, chiral primary amines have been explored and the primary−tertiary diamine−Brønsted acid salts are found to promote the cross-aldol reactions of aldehydes with high activity and syn selectivity. Among various vicinal diamines screened, l-phenylalanine derived
Synthesis of Enantiomerically Pure Alkylated <scp>d</scp>‐Erythritols and <scp>d</scp>‐Threitols from <scp>d</scp>‐Xylose—Structural Influences on Their Mesophasic Behavior
作者:S. Bachir‐Lesage、P. Godé、G. Goethals、P. Villa、P. Martin
DOI:10.1081/car-120019012
日期:2003.1.3
1‐O‐Alkyl and 2‐O‐alkyl‐d‐threitol enantiomers were derived from 5‐O‐alkyl and 5‐O‐benzyl‐1,2‐O‐isopropylidene‐α‐d‐xylofuranoses. The analogous erythrtol derivatives were also obtained from the same precursors via analogous d‐ribose monoacetals. Mesophasic behavior studies of these alditols and their alkylated d‐ribose and d‐xylose precursor, showed that the relative orientation of alkyl and OH groups
1- ø -烷基和2- ö -烷基- d -threitol对映异构体从5-推导ø -烷基和5- ö苄基1,2- ö异亚丙基α- d -xylofuranoses。类似的赤藓醇衍生物也通过类似的D-核糖单缩醛从相同的前体获得。这些糖醇以及中间相行为的研究它们的烷基化d -核糖和d -木糖前体,表明烷基和OH基的相对取向似乎是影响热致和溶致相变温度的主要结构要素。