28957-57-5 Usage
Check Digit Verification of cas no
The CAS Registry Mumber 28957-57-5 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 2,8,9,5 and 7 respectively; the second part has 2 digits, 5 and 7 respectively.
Calculate Digit Verification of CAS Registry Number 28957-57:
(7*2)+(6*8)+(5*9)+(4*5)+(3*7)+(2*5)+(1*7)=165
165 % 10 = 5
So 28957-57-5 is a valid CAS Registry Number.
28957-57-5Relevant articles and documents
Total synthesis of tetracyclic sesquiterpenoids: (+/-)-ishwarone
Piers, Edward,Hall, Tse-Wai
, p. 2613 - 2623 (2007/10/02)
A stereoselective total synthesis of the racemic modification of the tetracyclic sesquiterpenoid ishwarone (2) is described.Treatment of the known ketal aldehyde 19 with dibromomethylenetriphenylphosphorane gave the dibromo alkene 20, which was transforme