Publisher Summary This chapter elaborates the synthesis and chemistry of steroids and biologically related compounds. Several new procedures for the total synthesis of steroids have been developed. A novel synthesis of neither a 19- nor steroid was reported in which tert-butyl acetonedicarboxylate was alkylated and the product further condensed with the disubstituted cyclopentanedione to give the tricyclic intermediate. The utility and convenience of this procedure may permit it to be adapted to the syntheses of a large variety of useful steroids and steroid intermediates. Two new total syntheses of dl-estrone utilize the bicyclic aldehyde and the vinylketone as key intermediates. These are condensed respectively with m-methoxybenzyltriphenylphosphonium chloride and 2-methylcyclopentanedione to give the appropriate intermediates for ring closure. A total synthesis of norgestrel was discussed, in which the key step is the condensation of thylcyclopentanedione with the tetrahydropyran derivative. The preparation of 19-norprogesterone was also described in which diosgenin was converted to 19-nordiosgenin through the 6, 19-oxide and the 19-methylol derivatives.