Clemmensen reduction of diosgenin and kryptogenin: synthesis of [16,16,22,22,23,23-2H6]-(25R)-26-hydroxycholesterol

A new experimental protocol has been established for the Clemmensen reduction of diosgenin and kryptogenin with the aim to prepare deuterated isotopomers of (25R)-26-hydroxycholesterol. Uncontrolled deuteration has been achieved from diosgenin, whereas [16,16,22,22,23,23-2H6]-(25R)-26-hydroxycholesterol (1) can be synthesized from kryptogenin.