one tritium atom was lost from c-6 on conversion of the labelled beta-sitosterol into either 3beta-acetoxy-6-nitrostigmast-5-ene or stigmast-4-ene-3,6-dione , demonstrating that formation of the c-5-c-6 double bond of phytosterols also involves the elimination of the 6alpha-hydrogen atom of a precursor sterol .
C0041119
tritium
C0020275
hydrogen