The ionic Diels–Alder reaction of 1-vinyl-4-methyl-2,6,7-trioxabicyclo[2.2.2]octane. Retention of the ortho ester moiety through the use of the trioxabicyclo[2.2.2]octanyl protecting group
Abstract
1-Vinyl-4-methyl-2,6,7-trioxabicyclo[2.2.2]octane adds to 1,3-dienes at low temperatures under Lewis acid catalysis to give Diels–Alder adducts possessing the intact ortho ester moiety.