2-Methylene-19-nor-(23S)-25-dehydro-1alpha-hydroxyvitamin D3-26,23-lactone and 2-methylene-19-nor-(23R)-25-dehydro-1alpha-hydroxyvitamin D3-26,23-lactone
2-Methylene-19-nor-(23S)-25-dehydro-1alpha-hydroxyvitamin D3-26,23-lactone and 2-methylene-19-nor-(23R)-25-dehydro-1alpha-hydroxyvitamin D3-26,23-lactone