Neoclerodane Diterpenes from Amoora stellato‐squamosa

Abstract From the twigs of Amoora stellato‐squamosa , five new neoclerodane diterpenes have been isolated and characterized, methyl (13 E )‐2‐oxoneocleroda‐3,13‐dien‐15‐oate (=methyl (2 E )‐3‐methyl‐5‐[(1 S ,2 R ,4a R ,8a R )‐1,2,3,4,4a,7,8,8a‐octahydro‐1,2,4a,5‐tetramethyl‐7‐oxo‐naphthalen‐1‐yl]pent‐2‐enoate; 1 ), (13 E )‐2‐oxoneocleroda‐3,13‐dien‐15‐ol (=(4a R ,7 R ,8 S ,8a R )‐1,2,4a,5,6,7,8,8a‐octahydro‐8‐[( E )‐5‐hydroxy‐3‐methylpent‐3‐enyl]‐4,4a,7,8‐tetramethylnaphthalen‐2(1 H )‐one; 2 ), (3 α ,4 β ,13 E )‐neoclerod‐13‐ene‐3,4,15‐triol (=(1 R ,2 R ,4a R , 5 S ,6 R ,8a R )‐decahydro‐5‐[( E )‐5‐hydroxy‐3‐methylpent‐3‐enyl]‐1,5,6,8a‐tetramethylnaphthalene‐1,2‐diol; 3 ), (3 α ,4 β ,13 E )‐4‐ethoxyneoclerod‐13‐ene‐3,15‐diol (=(1 R ,2 R ,4a R ,5 S ,6 R ,8a R )‐1‐ethoxydecahydro‐5‐[( E )‐5‐hydroxy‐3‐methylpent‐3‐enyl]‐1,5,6,8a‐tetramethylnaphthalen‐2‐ol; 4 ), and (3 α ,4 β ,14 RS )‐neoclerod‐13(16)‐ ene‐3,4,14,15‐tetrol (=(1 R ,2 R ,4a R ,5 S ,6 R ,8a R )‐decahydro‐5‐[3‐(1,2‐dihydroxyethyl)but‐3‐enyl]‐1,5,6,8a‐tetramethylnaphthalene‐1,2‐diol; 5 ), together with two known compounds, (13 E )‐neocleroda‐3,13‐diene‐15,18‐diol ( 6 ) and (13 S )‐2‐oxoneocleroda‐3,14‐dien‐13‐ol ( 7 ).