Avermectin A1a (>90%)

(2S,2a'E,2a1'S,4'E,5S,6R,6'S,7'S,8'E,11'R,17a'R,20'R,20a'R)-6-((S)-sec-butyl)-2a1'-Hydroxy-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)-20'-methoxy-5,6',8',19'-tetramethyl-2a1',5,6,6',7',10',11',14',15',17a',20',20a'-dodecahydro-2'H,17'H-spiro[pyran-2,13'-[11,15]methano[1,5]dioxacyclooctadecino[9,8,7-cd]benzofuran]-17'-one; Spiro[11,15-methano-2H,13H,17H-furo[4,3,2-pq][2,6]benzodioxacyclooctadecin-13,2'-[2H]pyran] Avermectin A1a derivative; Antibiotic C 076A1a; L 676891;

CC[C@H](C)[C@H]1O[C@@]2(C[C@@H]3C[C@@H](C\C=C(/C)\[C@@H](O[C@H]4C[C@H](OC)[C@@H](O[C@H]5C[C@H](OC)[C@@H](O)[C@H](C)O5)[C@H](C)O4)[C@@H](C)\C=C\C=C\6/CO[C@@H]7[C@H](OC)C(=C[C@@H](C(=O)O3)[C@]67O)C)O2)C=C[C@@H]1C