Synthesis of the Enantiomerically Enriched Macrocyclic Lactones (+)-(S)- and (?)-(R)-Phoracantholide I and (+)-(S)-Tetradecan-13-olide
作者:Stephan Stanchev、Manfred Hesse
DOI:10.1002/hlca.19900730226
日期:1990.3.14
Synthesis of two naturally occurring macrocyclic lactones is described. (−)-(R)-Phoracantholide I ((−)-1; Scheme 2) was synthesized by asymmetric and chemoselective reduction of the side-chain CO group of (−)4-(1-nitro-2-oxocyclohexyl)butan-2-one ((−)-6) with (R)-Alpine-Hydride (47% ee). It was shown that the formation of only one diastereoisomer of the hemiacetal 5, by methylation with (i-PrO)2TiMe2
描述了两种天然存在的大环内酯的合成。通过不对称和化学选择性还原(-)4-(1-硝基-2-氧代环己基)丁烷的侧链CO基团合成(-)-(R)-邻甲酚内酯I((-)- 1 ;方案2) -2-一((-)- 6)与(R)-氢化铝(47%ee)。已经显示,通过热力学控制了通过与(i-PrO)2酮醛(-)- 2的(i-PrO)2 TiMe 2甲基化形成半缩醛5的仅一种非对映异构体。(+)-(S)-十四烷基十三内酯((+)- 10通过用旋光性硼氢化物还原二酮(±)-11,然后进行脱硝(方案3),获得)。
STANCHEV, STEPHAN;HESSE, MANFRED, HELV. CHIM. ACTA, 73,(1990) N, C. 460-467
作者:STANCHEV, STEPHAN、HESSE, MANFRED
DOI:——
日期:——
Michael Additions in Aqueous Media: “On-Water” and “In-Water” Processes from α-Nitro Ketones and Their Anions
作者:Giorgio Giorgi、Pilar López-Alvarado、Sonia Miranda、Jean Rodriguez、J. Carlos Menéndez
DOI:10.1002/ejoc.201201431
日期:2013.3
A variety of α,β-unsaturatedaldehydes and ketones gave very high-yielding Michael addition reactions with α-nitrocycloalkanones in water, at room temperature without added catalyst. These can be considered as one of the very few “on-water” Michael reactions known in the literature, because they took place in suspension or emulsion and at increased speed relative to the same transformations performed