(3.beta.)-Cholesta-5,7-dien-3-ol .DELTA.5,7-Cholesterol .DELTA.7-Cholesterol 434-16-2 5,7-Cholestandien-3.beta.-ol 7,8-Didehydrocholesterol 7-Dehydrocholesterin 7-Dehydrocholesterol Cholesta-5,7-dien-3-.beta.-ol Cholesta-5,7-dien-3-ol, (3.beta.)- Cholesta-5,7-dien-3.beta.-ol Cholesterol, 7-dehydro- Dehydrocholesterol NSC18159 Provitamin D3