Welcome to LookChem.com Sign In|Join Free


  • or


Post Buying Request

166757-19-3 Suppliers

Recommended suppliersmore

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

166757-19-3 Usage

Check Digit Verification of cas no

The CAS Registry Mumber 166757-19-3 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,6,6,7,5 and 7 respectively; the second part has 2 digits, 1 and 9 respectively.
Calculate Digit Verification of CAS Registry Number 166757-19:
173 % 10 = 3
So 166757-19-3 is a valid CAS Registry Number.

166757-19-3Relevant articles and documents

An Unusual Example of a 6-Endo-Dig Addition to an Unactivated Carbon-Carbon Triple Bond

Padwa, Albert,Krumpe, Keith E.,Weingarten, M. David

, p. 5595 - 5603 (2007/10/03)

Methyl 2-ethynyl>benzoate was prepared as an intermediate for subsequent conversion to an α-diazo ketone.Under the basic conditions used to hydrolyze the methyl ester, the neighboring hydroxyl functionality underwent reaction with the unactivated acetylenic group, producing a benzopyranyl-substituted α-diazoacetophenone.Treatment of this diazocarbonyl compound with a catalytic quantity of rhodium(II) mandelate afforded a novel dibenzocyclononenone derivative.The reaction proceeds via an initially formed oxonium ylide which rearranges further by means of a 1,2-alkyl shift.A prime factor in determining the direction of internal cyclization to the triple bond is the presence of the carbomethoxy group in the ortho position of the β-phenyl ring.Thus, in contrast with related systems which exhibit a clear preference for 5-exo-dig cyclization at the acetylenic center, the 6-endo-dig addition is the preferred pathway for the o-formyl- and o-carbomethoxy-substituted alkynyl alcohols.Careful monitoring of the reaction actually showed that the reaction proceeds by initial formation of the 5-exo-dig product followed by a novel rearrangement to the 6-endo product.

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)


What can I do for you?
Get Best Price

Get Best Price for 166757-19-3