Abstract: Compounds of formula (I) in which: R1 represents a hydrogen atom or an O-protecting group; R2 represents a hydroxyl, lower alkoxy, carboxaldehyde, lower alk-1-enyl or hydroxy- or lower alkoxy-substituted lower alkyl group; R3 represents a methyl group having ?- or ?-configuration; X represents a C1-3 alkylene group or a valence bond; Y represents a carboxaldehyde group or a group of formula —C(R4)(R5)OR1 where R1 is as defined above and R4 and R5, which may be the same or different, are each selected from hydrogen atoms, alkyl, alkenyl and alkynyl groups such that the total carbon content of R4 and R5 does not exceed three atoms, with the proviso that X is a valence bond when both R4 and R5 are other than hydrogen; and the dotted line signifies that a double bond may optionally be present at the 16(17)-position exhibit potent cell modulating activity, including antiproliferative and antiangiogenic effects.

Abstract: Compounds of formula (I) in which: R1 represents a hydrogen atom or an O-protecting group; R2 represents a hydroxyl, lower alkoxy, carboxaldehyde, lower alk-1-enyl or hydroxy- or lower alkoxy-substituted lower alkyl group; R3 represents a methyl group having &agr;- or &bgr;-configuration; X represents a C1-3 alkylene group or a valence bond; Y represents a carboxaldehyde group or a group of formula —C(R4)(R5)OR1 where R1 is as defined above and R4 and R5, which may be the same or different, are each selected from hydrogen atoms, alkyl, alkenyl and alkynyl groups such that the total carbon content of R4 and R5 does not exceed three atoms, with the proviso that X is a valence bond when both R4 and R5 are other than hydrogen; and the dotted line signifies that a double bond may optionally be present at the 16(17)-position exhibit potent cell modulating activity, including antiproliferative and antiangiogenic effects.

Abstract: 1-Hydroxy pregnacalciferol derivatives of formula (I) and their corresponding 5,6-trans isomers wherein R1 is hydroxyl or lower alkoxy and R2 is optionally hydroxylated or lower alkoxylated lower alkynyl and R1 is C(RA) (RB)CH3 where RA is optionally hydroxylated or lower alkoxylated lower alkynyl and RB is hydroxyl or lower alkoxy or RA and RB together represent oxo and R2 is hydrogen, hydroxyl or lower alkoxy, and R3 and R4 represent hydrogen atoms, exhibit anti-progesterone activity and may be useful as antineoplastic, antifertility, antiproliferative, immunosuppressive and/or antiinflammatory agents.

Abstract: 1-Hydroxy pregnacalciferol derivatives of formula (I) and their corresponding 5,6-trans isomers wherein R1 is hydroxyl or lower alkoxy and R2 is optionally hydroxylated or lower alkoxylated lower alkynyl or R1 is C(RA) (RB)CH3 where RA is optionally hydroxylated or lower alkoxylated lower alkynyl and RB is hydroxyl or lower alkoxy or RA and RB together represent oxo and R2 is hydrogen, hydroxyl or lower alkoxy, and R3 and R4 represent hydrogen atoms, exhibit anti-progesterone activity and may be useful as antineoplastic, antifertility, antiproliferative, immunosuppressive and/or antiinflammatory agents.

Abstract: 1-Hydroxy pregnacalciferol derivatives of formula (I) and their corresponding 5,6-trans isomers wherein R1 is hydroxyl or lower alkoxy and R2 is optionally hydroxylated or lower alkoxylated lower alkynyl or R1 is C(RA) (RB)CH3 where RA is optionally hydroxylated or lower alkoxylated lower alkynyl and RB is hydroxyl or lower alkoxy or RA and RB together represent oxo and R2 is hydrogen, hydroxyl or lower alkoxy, and R3 and R4 represent hydrogen atoms, exhibit anti-progesterone activity and may be useful as antineoplastic, antifertility, antiproliferative, immunosuppressive and/or antiinflammatory agents.