Welcome to LookChem.com Sign In|Join Free

CAS

  • or

828938-19-8

Post Buying Request

828938-19-8 Suppliers

Recommended suppliersmore

  • Product
  • FOB Price
  • Min.Order
  • Supply Ability
  • Supplier
  • Contact Supplier

828938-19-8 Usage

Check Digit Verification of cas no

The CAS Registry Mumber 828938-19-8 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 8,2,8,9,3 and 8 respectively; the second part has 2 digits, 1 and 9 respectively.
Calculate Digit Verification of CAS Registry Number 828938-19:
(8*8)+(7*2)+(6*8)+(5*9)+(4*3)+(3*8)+(2*1)+(1*9)=218
218 % 10 = 8
So 828938-19-8 is a valid CAS Registry Number.

828938-19-8Upstream product

828938-19-8Relevant articles and documents

Copper-mediated regio- and stereoselective 12β-hydroxylation of steroids with molecular oxygen and an unexpected 12β-chlorination

Sch?necker, Bruno,Lange, Corinna,Zheldakova, Tatjana,Günther, Wolfgang,G?rls, Helmar,Vaughan, Gavin

, p. 103 - 114 (2005)

It is shown, that copper(I) complexes of 17-(2-iminomethyl)pyridino steroids (17-IMPY steroids) can react with molecular oxygen followed by a regio- and stereoselective γ-hydroxylation in 12β-position. After decomplexation and hydrolysis of the IMPY group 12β-hydroxy-17-ketones are available in practical useful yields. IMPY compounds are simple to prepare by condensation of oxo compounds with (2-aminomethyl)pyridine. In the cases of 17-IMPY steroids the yields in the hydroxylation procedure of an unactivated CH2 group are higher by starting with copper(II) complexes, reduction with benzoin/triethylamine in acetone and reaction with molecular oxygen in comparison to the direct reaction of copper(I) complexes with molecular oxygen in acetone. Employing the procedure in dichloromethane as solvent starting with copper(II) complexes surprisingly the 12β-chloro compound could be isolated next to the hydroxylation product. This regio- and stereoselective γ-chlorination takes place also in acetone, when triethylammonium chloride is added to the reaction mixture. Oxygen is necessary for this reaction. The mechanistic and stereochemical aspects of these new reactions are discussed. Comparison of the different yields of steroids with different A-ring [3-methoxy-estra-1,3,5(10)-triene and 3β-hydroxy-androst-5-ene] pointed out to a subtle influence of the molecular structure far from the reaction centre on these reactions. The successful hydroxylation of the IMPY derivative of 3β-hydroxy-androst-5-ene-17-one shows the tolerance of a homoallylic system against this oxidation procedure. By Oppenauer oxidation 12β-hydroxy- androst-4-ene-3,17-dione is available. The hydroxylation procedure opens a short way to 12β-hydroxy-17-oxo steroids, which are difficult to obtain by other routes. Graphical Abstract.

Post a RFQ

Enter 15 to 2000 letters.Word count: 0 letters

Attach files(File Format: Jpeg, Jpg, Gif, Png, PDF, PPT, Zip, Rar,Word or Excel Maximum File Size: 3MB)

1

What can I do for you?
Get Best Price

Get Best Price for 828938-19-8