Conversion of androstenolone to pregnenolone

Steroidal Aphidicolin Analogues Derived from Pregnenolone

The conversion of pregnenolone into the 3β,5α-, 3α,5α-, 4β,5α-, 3α,4α-, 3α,4β- and 3α,4α-dihydroxy derivatives of 17β-hydroxymethyl-5β-androstane as steroidal analogues of the diterpenoid DNA polymerase α inhibitor, aphidicolin, is described.

Synthesis and anti-HIV activity of cosalane analogues incorporating two dichlorodisalicylmethane pharmacophore fragments

A new series of cosalane analogues incorporating two fragments of the dichlorodisalicylmethane pharmacophore has been synthesized. In order to identify the position for the attachment of the pharmacophore fragments to the steroid ring that results in the most potent analogues, two types of compounds were designed. In the first type, the two pharmacophore fragments were attached at C-3 and C-17 of the steroid ring by using appropriate linker units. In the second type, both pharmacophore groups were connected to C-3 of the steroid through an alkenyl chain containing an amide moiety. All of the new compounds displayed antiviral activity versus HIV-1(RF), HIV-1(IIIB), and HIV-2(ROD) in cell culture. The relative potencies of the compounds resulting from the two attachment strategies were found to depend on the viral strain as well as the cell type. Overall, the attachment of the second pharmacophore did not result in either a large gain or a large loss in anti-HIV activity, and the results are therefore consistent with the hypothesis that the two pharmacophores act independently, and one at a time, with positively charged amino acid side chains present on the surface of gp120 and CD4.

Exploration of the effects of linker chain modifications on anti-HIV activities in a series of cosalane analogues

The effects of linker chain modifications were investigated in a series of cosalane analogues. The modifications investigated included: (1) shortening the three-carbon linker chain between the dichlorodisalicylmethane and the cholestane moiety by one carbon atom; (2) lengthening the linker chain by one carbon; (3) hydrogenation of the double bond in the linker chain; (4) changing the point of attachment of the linker chain from C-3 to C-6; (5) insertion of a phosphate between the steroid and the linker chain. With the exception of the phosphate modification, which abolished anti-HIV activity and increased cytotoxicity, the linker chain modifications produced relatively minor changes in anti-HIV activity and increased cytotoxicity, the linker chain modifications produced relatively minor changes in anti-HIV potency. The steroid and attached linker chain of cosalane therefore appear only to provide a general lipophilic appendage for the dichlorodisalicylmethane pharmacophore.

Long-acting contraceptive agents: cyclopropyl and cyclobutyl esters of norethisterone

Several esters of norethisterone (17 alpha-ethynyl-17 beta-hydroxyestr-4-en-3-one) with carboxylic acids containing a cyclopropyl or cyclobutyl ring have been synthesized and the stereochemistries of the side-chains determined.