Competitive Silyl–Prins Cyclization versus Tandem Sakurai–Prins Cyclization: An Interesting Substitution Effect
作者:Alberto Diez‐Varga、Héctor Barbero、Francisco J. Pulido、Alfonso González‐Ortega、Asunción Barbero
DOI:10.1002/chem.201403421
日期:2014.10.20
allylsilyl alcohols without allylic substituents, the reaction gives dioxaspirodecanes, which are the products of a tandemSakurai–Prinscyclization. In contrast, allylsilyl alcohols with an allylic substituent (R2≠H) selectively provide oxepanes, thus corresponding to a direct silyl–Prinscyclization. Both types of product are obtained with excellent stereoselectivity. Theoretical studies have been performed
Efficiency of Acid- and Mercury-Catalyzed Cyclization Reactions in the Synthesis of Tetrahydrofurans from Allylsilyl Alcohols
作者:Francisco J. Pulido、Asunción Barbero、Patricia Val、Alberto Diez、Alfonso González-Ortega
DOI:10.1002/ejoc.201200666
日期:2012.9
The scope of the acid-catalyzed and mercury-catalyzed cyclization reactions of allylsilyl alcohols is described. This methodology has been found to be an efficient approach to the synthesis of highlysubstitutedtetrahydrofurans. The stereoselectivity of the cyclization is dependent both on the substitution of the starting alcohol and on the catalyst. A plausible mechanism has been proposed that is