Asymmetric Synthesis of (+)‐Altholactone: A Styryllactone Isolated from Various Goniothalamus Species

The asymmetric total synthesis of (+)‐altholactone ( 1 ), a member of the styryllactone family of natural products displaying cytotoxic and antitumor activities, is described. Key steps include a RAMP‐hydrazone α‐alkylation (RAMP=( R )‐1‐amino‐2‐methoxymethylpyrrolidine) of 2,2‐dimethyl‐1,3‐dioxan‐5‐one, a boron‐mediated aldol reaction, a six‐ to five‐membered ring acetonide shuffling, an oxidative 1,5‐diol to δ‐lactone conversion and a stereoselective ring‐closure to generate the annulated tetrahydrofuran moiety with inversion of configuration.