Method of preparing 1-alpha-hydroxyvitamin D and 1-alpha-hydroxy-previtamin D compounds, and adduct of a previtamin D or tachysterol compound with a suitable dienophile.

摘要

The invention relates to a method of preparing 1a-hydroxyvitamin D or 1a-hydroxy-previtamin D compounds by hydroxylating the 1α-position of an adduct of a previtamin D compound with a suitable dienophile, in which adduct optionally present hydroxy group or hydroxy groups is or are protected, if desired, and after removai of the protecting group or groups, isolating the 1a-hydroxyvitamin D or 1α-hydroxy-previtamin D compound.

The invention also relates to 1α-hydroxy-previtamin D compounds.

The invention further relates to an adduct of a previtamin D or tachysterol compound with a dienophile of the general formula
in which A' and B' are equal and represent methoxy groups or ethoxy groups, or in which A' and B' together constitute a phenylimino or α-phenylene group.