Hetero diels-alder vs mukaiyama aldol pathways in the reaction of monoactivated dienes and aldehydes. A lewis acid study
作者:M.Teresa Mujica、María M. Afonso、Antonio Galindo、J.Antonio Palenzuela
DOI:10.1016/0040-4020(95)01031-9
日期:1996.2
effect of Lewisacid on the reaction of 2-monoactivated dienes and aldehydes was studied searching for more general reaction conditions than those previously published. It was found that BF3·OEt2 in diethyl ether gave the best yields of Dieis-Alder adducts with good endo/exo selectivities. The Mukaiyama aldol-Michael cyclization pathway which has been reported to occur with this Lewisacid in the reaction
A versatile approach to cyclic ethers. Synthesis of disubstituted oxepanes and oxocanes
作者:M.Teresa Mujica、María M. Afonso、Antonio Galindo、J.Antonio Palenzuela
DOI:10.1016/s0040-4039(00)76919-x
日期:1994.5
A synthetic sequence for the preparation of α,α′-disubstituted cyclic ethers of various ring sizes and either relative stereochemistry (cis or trans) is presented. It is based on the hetero Diels Alder reaction of a monoactivated diene and an aldehyde, yielding a silylenol pyrone which is transformed into a linear ether. This ether is cyclized by an intramolecular nucleophilic substitution reaction