1172607-71-4

Upstream product

• 1258-35-1 (3S,5R,6R,8S,9S,10R,13R,14S,17R)-5-bromo-6-hydroxy-10,13-dimethyl-17-((R)-6-methylheptan-2-yl)hexadecahydro-1H-cyclopenta[a]phenanthren-3-yl acetate 
• 64-17-5 ethanol 
• 1256-83-3 Acetic acid (3S,5S,8S,9S,10R,13R,14S,17R)-17-((R)-1,5-dimethyl-hexyl)-10,13-dimethyl-6-oxo-hexadecahydro-cyclopenta[a]phenanthren-3-yl ester 

Relevant academic research and scientific papers

Photochemistry of cyclic α-hydroxy ketones. I. The nature and genesis of the photoproducts from steroidal 5-hydroxy 6-keto steroids and compounds

Photolyses of 5-hydroxy-5α- and 5β-cholestan-6-one and their 3β-acetoxy- and 3β-benzyloxy derivates in benzene or ethanol proceed stereospecifically with retention of configuration at C-5 to give the corresponding lactones, 6-oxa-B-homocholestan-7-ones.Photolyses of 3β-acetoxy-7α-deutero-5-hydroxy-5α- and 5β-cholestan-6-ones also proceed sterospecifically to give the corresponding 5-deutero lactones. 3β-Acetoxy-5-deuteroxy-5α- and 5β-cholestan-6-one give on irradiation 1:3 and 7:1 mixtures, respectively, of the corresponding 7aα- and 7aβ-deutero lactones.Irradiation of 3β-acetoxy-5-methoxy-5α-cholestan-6-one in ethanol leads to the stereoselective formation of ethyl 3β-acetoxy-5-methoxy-5,6-seco-5α-cholestan-6-oate, while that of 3β-acetoxy-5α-cholestan-6-one gives mainly photoreduction products.These observations are interpreted in terms of α-cleavage of the C-5 - C-6 bond of the ketols to give alkyl acyl diradicals that undergo hydrogen transfer to give hydroxy ketenes, which then form the lactones.It is proposed that retention of configuration at C-5 results from two major factors - the nonplanar geometry of the hydroxyalkyl radical center, and fast hydrogen transfer in the diradical, the latter resulting from restricted rotation about the C-9 - C-10 bond.The specific transfer of the 7α-deuterium atom in the 7α-deutero ketols is attributed to these factors and to the preferred direction of opening to the diradical on α-cleavage.The O-deuterium labelling results are interpreted in terms of product development control in the conversion of the hydroxy ketenes to the lactones and are in accord with restricted rotation about the C-9 - C-10 bond.The photolysis of 3β-acetoxy-5-amino-5α-cholestan-6-one proceeds stereoselectively to give the 5β-lactam analogue of the 5β-lactone formed from the analogous 5α-ketol.

Reaction of Organic Halides with Chlorotris(triphenylphosphine)cobalt(I)

Reaction of various types of organic halides with a monovalent cobalt complex, chlorotris(triphenylphosphine)cobalt(I) is described.Reaction of benzylic monohalides, dihalides and trihalides with CoCl(Ph3P)3 gave a coupling product with formation of a carbon-carbon single bond, double bond and triple bond, respectively, under mild and non-basic conditions.Dehalogenation of non-benzylic vicinal dihalides with the reagent took place cleanly to give an olefin in high yield.Reductive coupling of allylic halides using the reagent afforded regioselectively a 1,5-diene with retention of the stereochemistry of the carbon-carbon double bond of the allylic halides used.By using this reaction, (E,E,E,E)-squalene was stereospecifically synthesized from (E,E)-farnesyl bromide.Reaction of halohydrins with CoCl(Ph3P)3 gave exclusively a ketone in the presence of an amine or olefin through an alkylcobalt intermediate.A 1,2-hydrogen shift is involved in this reaction.Keywords - chlorotris(triphenylphosphine)cobalt(I); coupling reaction; benzylic halides; allylic halides; synthesis of 1,5-diene; squalene; halohydrin; ketone synthesis.