New compounds identified in agarwood (<i>Aquilaria agallocha</i> Roxb.)

Abstract

Abstract 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[7.2.1.0 1,6 ]dodecane‐2‐spiro‐2′‐oxirane (1) (epoxy‐β‐agarofuran), ( 1S,2S,6S,9R )‐6,10,10‐trimethyl‐11‐oxatricyclo[7.2.1.0 1,6 ]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 [7.2.1.0 1,6 ]dodecane‐2‐spiro‐2′‐oxirane ( 5 ), ( 1S,2R,6S,9R )‐6,10,10‐trimethyl‐11‐oxatricyclo[7.2.1.0 1,6 ] 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 13 C NMR data of agarospirol ( 9 ), published earlier, 1 are corrected. The assignments are supported by 1D‐INADEQUATE experiments.