Abstract: A process for the preparation of 5,6-cis- and 5,6-trans-10,19-dihydro-vitamin D derivatives which comprises hydrogenating a corresponding vitamin D compound in the presence of a ligand-coordinated homogeneous transition metal catalyst whereby the C-19 methylene group of the vitamin D compound is converted into a methyl group.

Abstract: The Specification describes a synthetic route for the preparation of a 9,11-dehydro-3-oxygenated 17.alpha.-hydroxy-20-ketopregnane which comprises the steps (i) electrophilically fluorinating a saturated 9,11-unsubstituted 3-oxygenated-17.alpha.-(esterified hydroxy)-20-ketopregnane, (ii) dehydrofluorinating the resulting 9.alpha.-fluorosteroid, if desired after transformations elsewhere in the molecule have been effected, and (iii) cleaving the ester group at the 17.alpha.-position to generate a 17.alpha.-hydroxy group.

Abstract: Saturated organic compounds containing a hydrogen atom bound to a tertiary carbon atom may be electrophilically fluorinated by reaction with an electrophilic fluorinating agent such as molecular fluorine or trifluoromethyl hypofluorite under conditions whereby the formation of free fluorine radicals is suppressed, e.g. by the presence of a free radical inhibitor such as oxygen or nitrobenzene, the reactants being substantially homogeneously dispersed in a liquid medium, e.g. a solvent medium such as fluorotrichloromethane or chloroform/fluorotrichloromethane, so that the said hydrogen atom is electrophilically replaced by a fluorine atom. The fluoroination is highly selective and, in the case of complex substrates such as saturated steroids which contain a number of tertiary C--H bonds, may be substantially completely confined to replacement of the hydrogen atom at the tertiary carbon atom which has the highest electron density about the C--H bond.

Abstract: Compounds of the general formula ##STR1## are provided wherein the substituents R, which may be the same or are different, represent hydrogen atoms or hydrocarbyl groups and the groups R.sup.1 represent hydrocarbyl groups or adjacent pairs of substituents R, or R and R.sup.1 together with the carbon atoms to which they are attached may constitute a non-aromatic ring structure, said hydrocarbyl groups or ring structure if desired carrying one or more substituents. Preferred compounds include steroid 1,4-diene-3-thiones of the cholestane, androstane, oestrane and pregnane series. Compositions containing these compounds are also provided.

Abstract: 11-Halo derivatives of amitriptyline and its analogues, i.e. 5-(1'-halo-3'-aminoprop-1'-yl-idene)-5H-dibenzo[a,d]-10,11-dihydrocyclohep tenes and corresponding 11-oxa analogues as well as the acid addition salts thereof, have notable anti-depressant and tranquillising activity. They are prepared by reacting a 5-(3'-aminoprop-1'-ylidene)-5H-dibenz[a,d]-10,11-dihydrocycloheptene or an 11-oxa analogue thereof, or an acid addition salt thereof, with an electrophilic halogenating agent.

Abstract: There is described the preparation of a mononitrate ester of a diol by photolysing in the presence of molecular oxygen a nitrite ester of an alcohol having a hydrogen atom conformationally adjacent to the hydroxy group and in which the atoms joining the hydrogen atom and the hydroxyl group include at least two adjacent atoms forming part of a ring.