Transformed steroids. 180. Stereospecific transformation of 17Β-hydroxy-17α-ethynylsteroids into various 17α-substituted 17Β-ethynylsteroids

The use of a dicobalt hexacarbonyl protective group permitted us to carry out the stereospecific conversion of 17-hydroxy-17-ethynylsteroids into branched 17-R-substituted 17-ethynylsteroids (R-OH, OAc, OMe, NCS, and F).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 675–681, March, 1990.     

Transformed steroids. 112. 17α-Fluoro-16α-amino-20-ketosteroids

Conclusions The reaction of 16,17-epiminopregnenolone 20-carbethoxyhydrazone with HF and subsequent hydrolysis leads to 17-fluoro-16-amino-20-ketosteroids.See [1] for Communication 111.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1637–1639, July, 1980.     

An efficient method for converting 17-oxo- into 17-acetyl steroids

A study of certain reaction parameters of the recently described procedure for converting ketones to the corresponding carbonitriles using tosylmethyl isocyanide, has led to a modified method suitable for the efficient synthesis of 17-cyanosteroids. These products readily undergo methylation to give the corresponding 17-acetyl compounds. This two-step conversion of steroidal 17- to 20-ketones proceeds in excellent overall yields, and constitutes a particularly mild and simple alternative method to those hitherto used for this purpose.     

Hypoiodite reactions of steroids. X. Fragmentation of 20-hydroxysteroid (17-iodoandrostanes)

In the hypoiodite reaction of 20-hydroxy steroids, 17α- and 17β-iodo androstanes are formed as by-products by fragmentation of the intermediate alkoxy radicals. The epimeric iodides show antipodal CD.- and ORD.- curves in accordance with their absolute configuration at the relevant chiral centre C(17).     

Transformed steroids. Communication 140. 17α-aza-D-homoandrostanes — Their properties and transformations

Conclusions The reaction of 17-acetylamino-17-aza-D-homoandrostene with mesitylenesulfonylhydroxyl-amine proceeds with the formation of steroid amidrazones.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 914–918, April, 1986.     

Transformed steroids. 181. Synthesis of 16α,17α-cyclohexano-19-norprogesterone

Oxidative functionalization of the 19-angular methyl group of pregna-D₆-pentarane with its subsequent removal gave 16,17-cyclohexano-19-norprogesterone.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1636–1638, July, 1990.     

Conversion of biomass to selected chemical products

This critical review provides a survey illustrated by recent references of different strategies to achieve a sustainable conversion of biomass to bioproducts. Because of the huge number of chemical products that can be potentially manufactured, a selection of starting materials and targeted chemicals has been done. Also, thermochemical conversion processes such as biomass pyrolysis or gasification as well as the synthesis of biofuels were not considered. The synthesis of chemicals by conversion of platform molecules obtained by depolymerisation and fermentation of biopolymers is presently the most widely envisioned approach. Successful catalytic conversion of these building blocks into intermediates, specialties and fine chemicals will be examined. However, the platform molecule value chain is in competition with well-optimised, cost-effective synthesis routes from fossil resources to produce chemicals that have already a market. The literature covering alternative value chains whereby biopolymers are converted in one or few steps to functional materials will be analysed. This approach which does not require the use of isolated, pure chemicals is well adapted to produce high tonnage products, such as paper additives, paints, resins, foams, surfactants, lubricants, and plasticisers. Another objective of the review was to examine critically the green character of conversion processes because using renewables as raw materials does not exempt from abiding by green chemistry principles (368 references).