Isolation of S-(3-oxoundecyl) thioacetate, bis-(3-oxoundecyl) disulphide, (−)-3-hexyl-4,5-dithiacycloheptanone, and S-(trans-3-oxoundec-4-enyl) thioacetate from Dictyopteris - Roller, P; Au, K; Moore, R E (Chem Commun, 1971)