Ozonolysis of (R, Z)-12-hydroxy-9-octadecenoic acid (which makes up 80-90% of castor oil) in MeOH followed by reduction of peroxide intermediates with Me2S over HCl as catalyst, gave (R)-1,3-nonanediot and (R)-3-hydroxynonanal dimethyl acetal. Glycerol esters were hydrolyzed and glycerol and salts were removed to yield enantiornerically pure 98% acetal. This was used to prepare (R)-rdecalactone, (R)-delta-undecalactone and (S)-3-nonanol and also some nitrogen derivatives. (R)-1,3-nonanediot was used to resolve dl-menthone via diastereoisomeric acetals.