Doramectin Impurity 11

(1S,2'R,3'S,6'S,7R,10R,11R,14E,16E,18S,19S,20E,23R) -19-{[ (2R,4S,5S,6S) -5-{[ (2S,4S,5S,6S) -5-hydroxy-4-methoxy-6-methyl-3,4,5,6-tetrahydro-2H-pyran-2-yl]oxy}-4-methoxy-6-methyl-3,4,5,6-tetrahydro-2H-pyran-2-yl]oxy}-2'-cyclohexyl-3',9,18,20-tetramethyl-2',3'-dihydrospiro[2,4,5,12,24-pentaoxapentacyclo[21.3.1.06,11.06,14.03,7]heptacosa-8,14 (15),16,20-tetraene-25,6'-pyran]-10-ol; (2S,2a'E,4'E,5S,6R,6'S,7'S,8'E,11'R,15'S,17a'R,20'R,20a'R) -6-cyclohexyl-7'- (((2R,4S,5S,6S) -5- (((2S,4S,5S,6S) -5-hydroxy-4-methoxy-6-methyltetrahydro-2H-pyran-2-yl) oxy) -4-methoxy-6-methyltetrahydro-2H-pyran-2-yl) oxy) -5,6',8',19'-tetramethyl-5,6,6',7',10',11',14',15',17',17a',20',20a'-dodecahydro-2'H-spiro[pyran-2,13'-[2a1,17]epidioxy[11,15]methano[1,5]dioxacyclooctadecino[9,8,7-cd]benzofuran]-20'-ol