Synonyms: HalichondrinA, 12,13-dideoxy-50-de(1,3,4-trihydroxybutyl)-50-(1,4,5-trihydroxypentyl)-;Dispiro[5H-furo[3,2-b]pyran-5,5'-[5H]furo[3,2-b]pyran-2'(3'H),23''(6''H)-[1,5:8,11:14,18]triepoxy[30,32]ethano[2,5]methano[2H,5H,28H]furo[2',3':5,6]pyrano[4,3-b]furo[2'',3'':5',6']pyrano[2',3':5,6]pyrano[3,2-i][1,4,8]trioxacyclopentacosin],halichondrin A deriv.; Halistatin 3; Neohomohalichondrin B;Dispiro[5H-furo[3,2-b]pyran-5,5'-[5H]furo[3,2-b]pyran-2'(3'H),23''(6''H)-[1,5:8,11:14,18]triepoxy[30,32]ethano[2,5]methano[2H,5H,28H]furo[2',3':5,6]pyrano[4,3-b]furo[2'',3'':5',6']pyrano[2',3':5,6]pyrano[3,2-i][1,4,8]trioxacyclopentacosin]-28''-one,tetracontahydro-7,7',16'',26''-tetramethyl-10'',17''-bis(methylene)-2-(1,4,5-trihydroxypentyl)-,(1''S,2S,2'S,2''R,3aS,3'aS,3''aR,3''bS,5R,5''S,7S,7'S,7aS,7'aS,8''S,11''S,14''S,16''R,18''R,19''aS,20''aS,21''aR,24''aR,25''aS,26''S,26''aR,30''R,31''aS,32''S,33''aR)-