A process for the preparation of pregnane derivatives of the formula ##STR1## wherein R.sub.1 is methyl or ethyl and R.sub.2 is methyl, ethyl, formyl, or acetyl, comprises reacting a nitrate ester of the formula ##STR2## wherein R.sub.1 is as above, in the presence of a catalytic amount of a mercury salt of a lower carboxylic acid with formic acid or acetic acid in a dipolar aprotic or basic solvent or with methanol or ethanol in an aprotonic, especially water-miscible, solvent in the presence of a mineral acid.
一种制备式的孕烷衍
生物的方法##STR1##其中R.sub.1为甲基或乙基,R.sub.2为甲基、乙基、甲酰基或乙酰基,包括在存在下述式的
硝酸酯的情况下反应##STR2##其中R.sub.1如上所述,在低级
羧酸的
汞盐的催化下与
甲酸或
乙酸在极性非质子或碱性溶剂中,或在无质子,特别是亲
水性的溶剂中与
甲醇或
乙醇在矿酸的存在下反应。