Abstract: The invention pertains to vitamin D amide derivatives of formula (I). These novel 1.alpha.-hydroxy vitamin D derivatives and their 20-epi analogues comprise compounds of formula (I) and corresponding 5,6-trans isomers, where Y represents an alkylene or alkenylene group containing up to four carbon atoms; R.sup.1 and R.sup.2 independently represent a hydrogen atom or a lower alkyl or cycloalkyl group, or R.sup.1 R.sup.2 N-- represents a heterocyclic group; and R.sup.3 and R.sup.4 independently represent a hydrogen atom or an 0-protecting group. Active compounds, in which R.sup.3 and R.sup.4 are hydrogen atoms or metabolically labile 0-protecting groups exhibit potent cell modulating effect, but minimal effect on calcium metabolism.

Abstract: The invention provides novel compositions for use in pharmaceutical and veterinary medicine which contain 1.alpha.-hydroxy vitamin D compounds. Particular compositions are described which contain steroids which induce or assist in combatting osteoporosis together with 1.alpha.-hydroxy vitamin D.sub.3 or 1.alpha.,25-dihydroxy vitamin D.sub.3. Methods of treatment of diseases are also provided including many which are resistant to vitamin D.sub.3, in particular bone diseases.

Abstract: The invention provides novel 1.alpha.-hydroxy vitamin D compounds and a method for their preparation from 1.alpha.-hydroxy-25-hydrogen cholesta-5,7-dienes by irradiation and isomerization techniques. The invention also includes the said 1.alpha.-hydroxy-25-hydrogen-cholesta-5,7-dienes and the corresponding cholest-5-enes.The new compounds may be obtained in a crystalline form substantially free from isomeric or other impurities arising from manufacture.

Abstract: 1-unsubstituted 5,6-trans vitamin D compounds are 1.alpha.-hydroxylated by Se.sup.IV oxidation in the presence of selenous acid at a pH in the range 3-9. The oxidation is preferably effected using a 1-unsubstituted-3-trihydrocarbylsilyloxy-5,6-trans vitamin D compound in the presence of a co-oxidant.

Abstract: The invention provides a compound of formula I ##STR1## where R.sup.1 represents hydrogen, lower alkanoyl or aryol, or tri-lower alkyl silyl, or a group R.sup.3 --O--CO-- (where R.sup.3 represents lower alkyl); R.sup.2 represents hydrogen, hydroxyl or fluorine and X represents --S--, --SO--, --SO.sub.2 --, --O--or --NR.sup.4 -- (where R.sup.4 represents hydrogen, lower alkyl or lower alkanoyl); the compounds are useful in the prophylaxis or management of cardiovascular disease through the regulation of serum cholesterol and a particularly useful compound is 23-thia-25-hydroxy-cholesterol.

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 fluorination 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: 1-Hydroxy-5,6-trans vitamin D compounds are prepared by oxidizing a 5,6-trans vitamin D compound using a selenic ester which may be formed in situ using selenous acid or selenium dioxide in the presence of an alcohol.

Abstract: N,N-difluoroamines are prepared by fluorination of compounds containing a >C.dbd.N-- bond using molecular fluorine or a hypofluorite in which the fluoroxy group is bonded to an inert electron attracting group, such hypofluorites including fluoroalkyl hypofluorites such as trifluoromethyl hypofluorite. The fluorination is advantageously conducted in the presence of an alkanol or other nucleophilic compound. Suitable starting materials include imino ethers and esters and aliphatic and aromatic Schiff's bases, use of the latter being particularly convenient.

Abstract: Novel compounds of general formula ##STR1## (where R.sup.1 and R.sup.2, which may be the same or different, are hydrogen atoms or alkyl groups; and R.sup.3 and R.sup.4, which may be the same or different, represent alkyl groups which may carry substituents, R.sup.4 alternatively representing a hydrogen atom; or R.sup.3 and R.sup.4 together with the intervening N represent a heterocyclic group or an acid-addition salt thereof) are provided, together with a process for their preparation. The new compounds are useful as antidepressants.

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: A method of contraception which comprises orally administering steroidal 11, 19-hemiacetals of 11-hydroxy-19-oxo compounds to human beings.