A Cope Rearrangement-Based Route to Hexahydroazulenes

Abstract

2-exo-Vinyl-7-alkylidenenorbornanes, readily prepared from fulvene Diels–Alder adducts, undergo smooth Cope rearrangement at elevated temperatures to produce hexahydroazulene derivatives.

Total Synthesis of (±)-Gracilioether F

“…With aldehyde 9a secured, we then focused on the synthesis of the pivotal 1,2-dioxane moiety, which would also pave the way toward the peroxide part in the gracilioether family, as well as toward our desired diol species 3. Aldehyde 9a was subjected to a classic Wittig olefination 14 to give alkene 10 in 75% yield (Scheme 3). However, we failed to obtain the relevant peroxide compound via the Diels−Alder cyclization between a similar diene lactone derived from lactone 10 and singlet oxygen, presumably due to the electron-deficient nature of the diene lactone.…”