Acid-Catalyzed Cyclization Reactions of Substituted Acetylenic Ketones: A new Approach for the Synthesis of 3-Halofurans, Flavones, and Styrylchromones
作者:Daniel Obrecht
DOI:10.1002/hlca.19890720305
日期:1989.5.3
Acetylenic acetals of type I(Scheme 1) and acetylenic ketones of type III(Scheme 1), 37 and 38(Scheme 7) are versatile synthetic precursors for the synthesis of various heterocycles by acid-catalyzed cyclization reactions. By this way, substituted 3-halofurans of type II and IV(Scheme 1) and flavones and styrylchromones (Scheme 7) can be synthesized in good-to-excellent yields. The high degree of regioselectivity
Thione Reductions for Preparation of Five-Membered Heterocycles
作者:D.R. Williams、J.L. Moore
DOI:10.1016/s0040-4039(00)81401-x
日期:——
Facile reductions with tri-n-butyltinhydride convert a variety of five-membered 1,3-disubstituted heterocyclic thiones to the corresponding saturated derivatives.
Provided herein are compounds of the formula (I):
as well as pharmaceutically acceptable salts thereof, wherein the substituents are as those disclosed in the specification. These compounds, and the pharmaceutical compositions containing them, are useful for the treatment of inflammatory diseases and disorders such as, for example, asthma and COPD.
Kinetic Resolution of Homoaldols via Catalytic Asymmetric Transacetalization
作者:Ilija Čorić、Steffen Müller、Benjamin List
DOI:10.1021/ja108642s
日期:2010.12.15
The highly enantioselective kinetic resolution of homoaldols via a transacetalization reaction has been achieved. A novel phosphoric acid, STRIP, based on a spirocyclic 1,1'-spirobiindane backbone was designed and identified as a superior catalyst for this transformation. Remarkably, both secondary and tertiary homoaldols gave equally excellent results.