合成路线1

Starting compound (I) is hydroxylated microbiologically by means of Botryodiplodia malorum to 3,7-dihydroxy-15beta,16beta-methylene-5-androsten-17-one (VIII), which is selectively acylated with pivalic anhydride to the monoacyl derivative (IX). Epoxidation of (IX) with tert-butyl hydroperoxide in hot toluene yields the epoxide (X), which by reaction with triphenylphosphine and CCl4 is converted to the chloroepoxide (Xl). The reactive elimination of Cl with Zn-acetic acid followed by hydrolysis with KOH yields 3,5-dihydroxy-15beta,16beta-methylene-6-androsten-17-one (XII), which is submitted to cyclopropanation with methyrene iodide and Zn/Cu in glyme yielding 3,5-dihydroxy-6beta,7beta:15beta,16beta-dimethyleneandrostan-17-one (XIII). The reaction of (XIII) with propargyl alcohol (XIV) by means of potassium ethoxide in THF affords the 17-(3-hydroxy-1-propyn-1-yl) derivative (XV), which is reduced with H2 over Pd/CaCO3 in THF to the corresponding 3-hydroxypropyl derivative (XVI). Finally, this compound is oxidized and cyclized by means of pyridinium dichromate to (VII) ), which is finally dehydrogenated by means of 2,3-dichloro-5,6-dicyanohenzoquinone in refluxing dioxane.