New compounds identified in agarwood (Aquilaria agallocha Roxb.)

Four new compounds have been isolated from agarwood oil (Aquilaria agallocha Roxb.) and their structures confirmed by synthesis: (1R,2R,6S,9R)‐6,10,10‐trimethyl‐ll‐oxatricyclo[7.2.1.01,6]dodecane‐2‐spiro‐2′‐oxirane (1) (epoxy‐β‐agarofuran), (1S,2S,6S,9R)‐6,10,10‐trimethyl‐11‐oxatricyclo[7.2.1.01,6]dodecane‐2‐carbaldehyde (2), (E)‐8,10‐undecadien‐2‐one (3) and 2,t‐3‐dimethyl‐r‐2‐(3‐methyl‐2‐butenyl)‐l‐cyclohexanone (4, absolute configuration unknown). Several of their diastereoisomers, such as (1R,2S,6S,9R)‐6,10,10‐trimethyl‐11‐oxatricyclo [7.2.1.01,6]dodecane‐2‐spiro‐2′‐oxirane (5), (1S,2R,6S,9R)‐6,10,10‐trimethyl‐11‐oxatricyclo[7.2.1.01,6] dodecane‐2‐carbaldehyde (6), (Z)‐8,10‐undecadien‐2‐one (7) and racemic 2,c‐3‐dimethyl‐r‐2‐(3‐methyl‐2‐butenyl)‐1‐cyclohexanone (8, racemate) were also synthesized and fully characterized. The 13C NMR data of agarospirol (9), published earlier,1are corrected. The assignments are supported by 1D‐INADEQUATE experiments.