Synonyms: Spiro[3,7-methano-1H,5H-2,6-benzodioxacyclooctadecin-5,2'-[2H]pyran],milbemycin B deriv.; Spiro[3,7-methano-1H,5H-2,6-benzodioxacyclooctadecin-5,2'-[2H]pyran]-1-one,3,3',4,4',5',6',7,8,11,12,16a,17,18,20a-tetradecahydro-16a-hydroxy-16-(hydroxymethyl)-18-methoxy-5',10,12,19-tetramethyl-,[3S-(3R*,5R*,5'R*,7S*,9E,12S*,13E,15E,16aR*,18R*,20aS*)]-;[3S-(3R*,5R*,5'R*,7S*,9E,12S*,13E,15E,16aR*,18R*,20aS*)]-3,3',4,4',5',6',7,8,11,12,16a,17,18,20a-Tetradecahydro-16a-hydroxy-16-(hydroxymethyl)-18-methoxy-5',10,12,19-tetramethylspiro[3,7-methano-1H,5H-2,6-benzodioxacyclooctadecin-5,2'-[2H]pyran]-1-one