Axial Chirality in Allenes, Biphenyls

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[@sagnikhalder8066]

Sir before watching this series of lectures i was very poor in stereochemistry , but this wonderful lectures helps me a lot to understand stereochemistry ❤❤❤😊 love form Kolkata 😊

[@amitbasak4819]

Good to know that. best wishes Amit Basak IISER Kolkata

[@ashishreshamiya6428]

Thanks sir for removing confusion.
All teachers say look from plane side in alleyl system.

[@ujjalghosh5066]

Thanks sir for giving your help it will help me in bsc chemistry honours

[@prabhuswamy4048]

Great sir
Real professor.

[@muthukrishnanmuthumuthukri7590]

Nice explanation sir

[@hasnaa4641]

Class is too good sir😊

[@srinivaschem07]

Awesome ❤️

[@DhananjayKumar-qp1dm]

Excellent sir

[@jishnuratheesan7115]

Nice class☺️

[@UmarAli-rz7uh]

Great lecture sir

[@lawrencewamala874]

am impressed more videos

[@elenawong4431]

thank you

[@yschemistry8879]

Thanks sir

[@micahstewart7118]

❤️

[@mourifat8659]

sir i am unable to find the sequence of these lectures . please provide a link on which i can have all the lectures in sequence on stereochemistry

[@maneesham3497]

Please explain the case of assigning absolute configuration in meta substituted biphenyls.

[@amitbasak4819]

Sorry for the late response. I can send some examples of meta substituted biphenyls by email. However just to let you know that you have to start giving preferences by looking at the individual phenyl rings through the C-C bond connecting the two phenyls. First check the ortho carbons, if there is no discrimination, then go to the meta carbon. Examples are needed to clarify this.

[@ajendralal2189]

Sir i think in biphnyl the configuration should be R BECAUSE 4TH gruop is in horizontal plane

[@abhinababanerjee638]

In the case of nomenclature of allene or bi-phenyl system as Ra or Sa if the lowest priority group(4) is in the horizontal bond , then interchanging of groups not to be done to put it into vertical bond ...
In that case 1-2-3 clockwise indicates Ra and 1-2-3 anti- clockwise indicates Sa ..it doesn't matter where the lowest priority group is .
The ans you are telling wrong is actually correct .

[@amitbasak4819]

Sorry for my delayed reply. Actually the projection representation of an allene is not a Fischer Projection. In this case, the 4th group will always be away from the observer irrespective of whether it is in the horizontal or vertical line.

[@ajayveeramalla5274]

Awesome vedio sir. I have one doubt while writing projection formula for allene molecule you consider left as right and right as left. Just I am thinking like that. Please explain if I am wrong. Once again I am very thankful to your contribution..

[@bibinshaji1419]

me to have the same doubt ...!!!!

[@chem-zone9812]

Brother, see the lecture again carefully
Sir, told it's not fisher projection.

[@amitbasak4819]

What are drawing here is a Newman projection and not Fischer Projection as correctly mentioned by CHEM-Zone

[@ghanashyams855]

@@amitbasak4819 sir how to draw newmanss projection in these type of molecules.. I didnt get that😞

[@TaliaOutwrong]

In the allene example, using F, Cl, Me & H, why were these not assigned priority using the Cahn Ingold Prelog system?

[@chem-zone9812]

CIP rule only for chiral centre
In allene , their is no chiral centre. It is chiral axis

[@amitbasak4819]

It is rightly said that priority assignment as per CIP system of all 4 groups are applicable to chiral centers (sp3 stereogenic centers). For optically active allenes, instead of chiral center, chiral axis is present. Note that molecules possessing chiral axis, all four groups need not to be different. Condition of chirality demands that the groups at two ends should be different . So the CIP system of priority assignment of all 4 groups will fail when the allene system is XYC=C=CXY.

[@rajkumari8306]

Sir please 🥺teach us group theoty