Welcome to LookChem.com Sign In|Join Free

CAS

  • or

20990-17-4

Post Buying Request

20990-17-4 Suppliers

Recommended suppliersmore

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

20990-17-4 Usage

Check Digit Verification of cas no

The CAS Registry Mumber 20990-17-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 2,0,9,9 and 0 respectively; the second part has 2 digits, 1 and 7 respectively.
Calculate Digit Verification of CAS Registry Number 20990-17:
(7*2)+(6*0)+(5*9)+(4*9)+(3*0)+(2*1)+(1*7)=104
104 % 10 = 4
So 20990-17-4 is a valid CAS Registry Number.

20990-17-4Relevant articles and documents

A convenient synthesis of 2,2,4-trimethylcyclohexane 1,3-dione: A useful precursor for the taxoid a ring

Miller, Michael L.,Ray, Partha S.

, p. 3991 - 3996 (1997)

A simple and inexpensive route to the title compound is described which should be readily amenable to large scale synthesis. Thus, reaction of 3- pentanone with methyl acrylate in the presence of sodium methoxide provided 2,4-dimethylcyclohexane-1,3-dione

Revisiting [3 + 3] route to 1,3-cyclohexanedione frameworks: Hidden aspect of thermodynamically controlled enolates

Ishikawa, Teruhiko,Kadoya, Ryuichiro,Arai, Masaki,Takahashi, Haruka,Kaisi, Yumi,Mizuta, Tomohiro,Yoshikai, Kazusa,Saito, Seiki

, p. 8000 - 8009 (2007/10/03)

We have revisited the traditional consecutive Michael-Claisen [3 + 3] process (MC-[3+3]) promising the synthesis of a cyclohexane-1,3-dione derivatives from nonactivated simple ketones and enoates and evaluated its potential in modern organic synthesis. Twenty to thirty examples were demonstrated to be effective. The reactions exhibited remarkable regioselectivity with the Michael addition proceeding through nucleophilic attack by the more hindered site of the ketones without exception. The subsequent Claisen condensation resulted in the formation of carbon-carbon bonds between less hindered site of the ketones and acyl carbon of the enoates. The MC-[3+3] process described is useful for the synthesis of Taxol A-ring synthons in multigram quantities and for the synthesis of other six-membered carbocyclic compounds. A number of control experiments have been conducted to provide strong support for the mechanism of this MC-[3+3].

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 20990-17-4