Total synthesis of seco-lateriflorone

Natural product-inspired rational design, synthesis and biological evaluation of 2,3-dihydropyrano[2,3- f ]chromen-4(8 H )-one based hybrids as potential mitochondrial apoptosis inducers

“…The upper layer was separated and dried over Na 2 SO 4 to afford pure 3-chloro-3-methyl-1-butyne (8, 3.0 g, 50%) as a colorless liquid. 1 Spectral data matched with literature report [62].…”

Unified synthesis of caged Garcinia natural products based on a site-selective Claisen/Diels–Alder/Claisen rearrangement

“…The most efficient proved to be a two-step procedure that involved propargylation of the more reactive C3, C5, and C6 phenols with 2-chloro-2-methylbutyne (21) in the presence of KI and K 2 CO 3 under CuI catalysis (25% yield) (23), followed by Lindlar reduction of the pendant alkynes (75% yield) (24). Drawing on previous experience with related structures (25,26), we heated 17a in DMF at 120°C and obtained a mixture of forbesione (1a) (49% yield) and isoforbesione (22a) (35% yield) (18).…”

Electrophilic aromatic prenylation via cascade cyclization

“…A known two-step method was used to introduce the propargyl groups of the bis ethers 14 and 17 . 37,38 When epoxide 14 was subjected to the standard cascade conditions (Scheme 3), the major product was the bridged A-ring ether 15 (47%) although it was accompanied by the hexahydroxanthene 16 in low yield (14%). The parallel reaction of the propargyl ether 17 gave only the bridged A-ring ether 18 (47%), and the hexahydroxanthene 19 was not detected in this reaction mixture.…”