Question

4. The final step in the biosynthesis of cholecalciferol (vitamin D3) in animals is an electrocyclic ring-opening of 7 dehydrocholesterol, followed by a 1,7 hydride shift. Use the Woodward-Fieser rules to determine what the max wavelength for 7-dehydrocholesterol should be. Animals UV/ sunlight 7-dehydrocholesterol Cholecalciferol Vitamin D

Answer 1

Answeb Imani wavelength For Thychocholesterol According to coord word fieser Rules is. Imax = 2840m 7-dehydrocholesterol Basic valuer diene = 215 nm q - Exo Cyclic double bond = 10nm ( 2x 5) Homo annular cliene (1X39) = 39org 4-alkyl substituents (485) = 200m Total = 2840m 1ls we take basic value 2140m, then Imoa = 2830m.