Abstract: The present invention relates to a method of producing a mixture of 5?-pregnane derivatives represented by the formula (II) and the formula (III), which is characterized by reacting a pregnane derivative represented by the formula (I) with a metal selected from alkali metals and alkaline earth metals in the presence of a proton donor and an amine and/or ammonia. According to the present invention, a method capable of producing 5?-pregnane derivatives useful as synthetic intermediates for squalamine, in a high yield from easily available raw materials, can be provided: wherein R1 is a hydroxyl-protecting group, and R2, R11 and R12 are each independently a hydrogen atom or a hydroxyl-protecting group.

Abstract: The present invention relates to a method of producing 5?-pregnane derivatives represented by the formula (II), which is characterized by reacting a pregnane derivative represented by the formula (I) with a metal selected from alkali metals and alkaline earth metals in the presence of a proton donor and an amine and/or ammonia. According to the present invention, a method capable of producing 5?-pregnane derivatives useful as synthetic intermediates for squalamine, in a high yield from easily available raw materials, can be provided: wherein R1 is a hydroxyl-protecting group, and R2, R11 and R12 are each independently a hydrogen atom or a hydroxyl-protecting group and R3 and R4 are each hydrogen atoms in combination form a bond.

Abstract: 7?-Hydroxy-pregn-4-en-3-one-20-carbaldehyde, a production method thereof and a method for producing 7?,21 -dihydroxy-20-methyl-pregn-4-en-3-one, which is useful as a synthetic intermediate for pharmaceuticals such as squalamine and the like, efficiently at high purity from the carbaldehyde.

Abstract: 7&agr;-Hydroxy-pregn-4-en-3-one-20-carbaldehyde, a production method thereof and a method for producing 7&agr;,21-dihydroxy-20-methyl-pregn-4-en-3-one, which is useful as a synthetic intermediate for pharmaceuticals such as squalamine and the like, efficiently at high purity from the carbaldehyde.

Abstract: A process for preparing pregnane derivatives represented by the formula (V), 1

Abstract: A cyclopropylacetylene derivative of the formula (V): is prepared by reacting a propynol derivative of the formula (I): with a propane derivative of the formula (VI): in the presence of a base in an amount of 2 or more equivalents relative to the propynol derivative to give a cyclopropane derivative of the formula (III): deprotecting the protecting group for the hydroxyl group of the cyclopropane derivative to give a cyclopropylpropynol derivative of the formula (IV): and subjecting the cyclopropylpropynol derivative to retro-ethynylation. In the above formulas R1, R2, R3, R4 and R5 represent hydrogen; or an alkyl, alkenyl, aryl or aralkyl group, each of which may have a substituent, R6 and R7 is hydrogen; or an alkyl, alkenyl, aryl or aralkyl group, each of which may have a substituent, or R6 and R7 taken together form a ring, R8 is a protecting group for the hydroxyl group and X and Y are each a leaving group.