Synthesis of key intermediates to 20(R)-and 20(S)-trifluoromethyl-23,24-dinor-25-hydroxy-cholesterol and VD3 analogs

Synthesis of 20(R)-and 20(S)-trifluoromethyl substituted steroids as the key intermediates (1a, 1b) to 23,24-dinor-20-trifluoromethyl-25-hydroxy-cholesterol and VD3 analogs, using trifluoromethyltrimethylsilane (CF₃SiMe₃) as a trifluoromethylating agent, was described.