Some of the methods available for comerting cholesterol into 7- dehydrochoJeateroI are reviewed for improving the yield of tmal product by modifying ditTerent steps. The allylic bromi­nation of choleateryl benzoate was done with l,3-dibromo-S,s'ilimethylhydantoin. In the dehydro­bromination of 7-bromocholeateryl benzoate an advantageous solvent namely ethyl benzoate was used for the isolation of 7-dehydrocholeateryl benzoate. The yield of provitamin D3 was 43% baaed on choleateryl benzoate.