10.1021/acs.jnatprod.6b00386
The study presents a protecting-group-free total synthesis of bioactive styryllactones, including (+)-goniodiol (1), (6S,7S,8S)-goniodiol (2), (-)-parvistone D (4), and (+)-parvistone E (6), inspired by their proposed biosynthesis pathway. The synthesis starts from trans-cinnamaldehyde (10) and involves key steps such as stereoselective Maruoka allylation to obtain compound (S)-11, acrylation to form acrylate 12, ring-closing metathesis to produce a-pyrone 8, and stereoselective epoxidation to yield goniothalamin oxides 9a and 9b. The final products are obtained through regio- and stereoselective epoxide ring-opening reactions in aqueous media. The study achieves high overall yields (72-75%) in just five steps, supporting the proposed biosynthesis pathway and providing a concise and efficient route for synthesizing these natural products with potential biological activities.