Question

FUSCLOU LAULU 1. Look carefully at the structure of the product - show how the 5a,6a- epoxycholestan-3B-ol name is derived by redrawing and labelling it accordingly. 2. Draw the other possible isomer arising from this reaction and name/label this in similar fashion:

Answer 1

Cholane CH3 L ITH CH3 н I| HO 3B-01 5a6a-Epoxycholestan-36-ol

Steroids are derivatives of the perhydrocyclopentaphenanthrene ring. The carbon skeleton can be numbered as below 12 CH3 11 CHE 1 2 410 15 A B 8 The ring junction can be cis or trans as shown below H3C HC 113 9 1 10 9 1 A 34 10 /B 15 AB 1516 56 7 H Here the ring junctions are trans Here the A, B ring junction is cis The a, ß designation are applied to the hydrogen at position 5 and 6. Thus, when the ring junction is trans, then the it become a series. Similarly, when the junction is trans, it becomes B series For any other substituents, if it is on the same general side of the molecule, then it is a substituent. The groups which lie on the bottom are regarded as B substituent Similarly, if the -R group is -H, then it is a Androstane. If it is -CH2-CH3, then is Pregnane and if the R group is -CH(CH3)CH2CH(CH3) it is Cholane

For part 2, details of the reaction are required