(S)-lactaldehyde 2-hydroxypropanal 598-35-6 Alpha-hydroxypropionaldehyde DL-lactaldehyde L-lactaldehyde Lactaldehyde Lactaldehyde (6CI,7CI,8CI) Propanal, 2-hydroxy Propanal, 2-hydroxy- (9CI) Racemic-glycerol formal lactald