2(3H)-Furanone, dihydro-4-(hydroxymethyl)-3-(6-methyl-1-oxoheptyl)-, (4R)- 2-Isocapryloyl-3R-hydroxymethyl-gamma-butyrolactone 51311-41-2 A Factor A-Factor (lactone) A-Factor (streptomyces) L-Factor (streptomyces)