Isolation and Bioinspired Synthesis of Lauenones A and B, Skeleton-Rearranged Diterpenoids with Antiadipogenic Activity from Croton laui

Two skeleton-rearranged labdane diterpenoids, lauenones A (1) and B (2) were isolated from Croton laui. Their bioinspired synthesis was accomplished in 9 and 10 steps, respectively, without using any protecting groups. Key steps include a semipinacol rearrangement and a substrate-controlled one-pot reaction cascade involving photooxidation and aldol condensation. Notably, both lauenones A and B exhibit antiadipogenesis in 3T3-L1 adipocytes by downregulating the differentiation factors and liposynthesis enzymes at mRNA transcription and protein expression levels.