Synthesis of substituted spiro[4.5]deca-3,6,9-triene-2,8-diones: an expeditious route to the spiro[4.5]decane terpene skeleton
作者:Richard A. Haack、Kenneth R. Beck
DOI:10.1016/s0040-4039(00)99532-7
日期:1989.1
Substitutedspiro[4.5]decanes are prepared in two steps in fair to moderate yield. A substituted 4-methoxyphenylacetyl chloride, prepared from the corresponding acid, is reacted with a substituted acetylene (or acetylene gas) in the presence of aluminum chloride in methylene chloride at 0°C to produce the corresponding substitutedspiroderivative.
Silica-Supported Silver Nitrate as a Highly Active Dearomatizing Spirocyclization Catalyst: Synergistic Alkyne Activation by Silver Nanoparticles and Silica
作者:Aimee K. Clarke、Michael J. James、Peter O'Brien、Richard J. K. Taylor、William P. Unsworth
DOI:10.1002/anie.201608263
日期:2016.10.24
Silica‐supported AgNO3 (AgNO3–SiO2) catalyzes the dearomatizing spirocyclization of alkyne‐tethered aromatics far more effectively than the analogous unsupported reagent; in many cases, reactions which fail using unsupported AgNO3 proceed effectively with AgNO3–SiO2. Mechanistic studies indicate that this is a consequence of silver nanoparticle formation on the silica surface combined with a synergistic