Zeolite-Mediated Cyclization of an Epoxide-Containing Polyene
摘要:
The utility of zeolites as promoters for the cyclization of an epoxide-containing polyene has been investigated. Reaction of polyene 1 with oven-dried 4 Angstrom molecular sieves (type A zeolite) proceeds efficiently to generate bicyclic alcohol 2 in a 90% isolated yield. The reaction is sensitive to a variety of factors, including solvent type, water content, and zeolite acidity. Reactivity is apparently due to the zeolite lattice, since alumina and silica either are unreactive or generate a complex mixture of epoxide ring-opened products. Compared to the aluminum-based Lewis acid Me(2)AlCl, the zeolite-promoted cyclization of 1 was a more facile reaction, providing excellent product recovery after filtration. These results indicate that zeolites represent a new class of promoters in biomimetic polyene cyclizations.
Zeolite-Mediated Cyclization of an Epoxide-Containing Polyene
摘要:
The utility of zeolites as promoters for the cyclization of an epoxide-containing polyene has been investigated. Reaction of polyene 1 with oven-dried 4 Angstrom molecular sieves (type A zeolite) proceeds efficiently to generate bicyclic alcohol 2 in a 90% isolated yield. The reaction is sensitive to a variety of factors, including solvent type, water content, and zeolite acidity. Reactivity is apparently due to the zeolite lattice, since alumina and silica either are unreactive or generate a complex mixture of epoxide ring-opened products. Compared to the aluminum-based Lewis acid Me(2)AlCl, the zeolite-promoted cyclization of 1 was a more facile reaction, providing excellent product recovery after filtration. These results indicate that zeolites represent a new class of promoters in biomimetic polyene cyclizations.
Zeolite-Mediated Cyclization of an Epoxide-Containing Polyene
作者:Stephanie E. Sen、Yan zhi Zhang、Steven L. Roach
DOI:10.1021/jo960745g
日期:1996.1.1
The utility of zeolites as promoters for the cyclization of an epoxide-containing polyene has been investigated. Reaction of polyene 1 with oven-dried 4 Angstrom molecular sieves (type A zeolite) proceeds efficiently to generate bicyclic alcohol 2 in a 90% isolated yield. The reaction is sensitive to a variety of factors, including solvent type, water content, and zeolite acidity. Reactivity is apparently due to the zeolite lattice, since alumina and silica either are unreactive or generate a complex mixture of epoxide ring-opened products. Compared to the aluminum-based Lewis acid Me(2)AlCl, the zeolite-promoted cyclization of 1 was a more facile reaction, providing excellent product recovery after filtration. These results indicate that zeolites represent a new class of promoters in biomimetic polyene cyclizations.