University:
Shippensburg University of Pennsylvania
Course:
CHM 121 | Chemical Bonding
Academic year:

2019
Views:

7

Pages:

11
Author:

Polemic

Steroids What are steroids A secondary alcoholi with 27 to 29 carbon atoms of animal and plant origin. (rystalline solids with M.P range of 100-200 degree"c. The term "Siero" means selid and of alcohol. • Number of compounds such as vit D, Bile acid, sex hormones, adrenal cortex hormones are belonging to steroids. The ste of steroids are based on 1,2-cyclopenteno. -phenanthrene skeleton → When steroids are distilled at 420°c yields. mainly Chrysere and a little Picene. Removal of terminal ring with addition of hydrogen atom at junction where the adjacent Jung is indicated by the Prefix DES followed by italic capital letter designnated the ring. → Naturally occuring steroids contain one or more additional heterocyclic ring fused on attached to ring D formed by the modification of the side chain. →Lengthening of side chain by insertion of one or more CH2 group indicated by Prefix HOMO. Occurrence Steroids occur in animal and plantoils and fats. They occurs as free or an ester of the higher fatty auds. •They are isolated from unsaponifiable Portion of oils and fats fati Strong Base + Sodium hydro Soap oxide (zapenification) → all parts of fats are not converted into soap.. then some part of fal which left called unsaperification part of fat- which comerted into steroid. Classification of sterols/ Zov Sterols →Animal Sources thotested Phyto sterols Plant sources 1. Campesterol Myco sterols Yeast and fungi sources 1. Cholesterol 2. Cholestanol 3. Coprasterol 2 Sitosterol 1. Ergosterol 2. Vit D 3. Stigmasteral Unknown Configuration if the configuration of the substituent is not known its bond to the nucleus is represented by a wary line and it is indicated by. One should specify the stereo chemical configuration of the steroid. Steroids shows optical isomerism. Geometrial isomerism 3. if some of the carbon atoms are missing in Steroid, the numbering of the remainder will not change in order to illustrate the above rule. Suppose angular methyl op is absent then also the numbering will not change.→ if the side chain does not contain a methylane gp. This is indicated by the Prefix NoR Preceded by the number of carbon atom that has disappeared Mentioned as 21 nor If the steroid does not contain angular methyl group this is again indicated by the Prefix NOR Preceded by the number of carbon in designaling the methyl group = if contraction of ring of a steroid, this is again indicated by the prefix NOR preceded a small capital letter Indicating the the ring CH