@RafaelNadal Hi

First up

I wanna say,that when there is a contradiction b/w indian and foreign authors,99% of the time,foreign authors are correct(unless the indian author has referred a proper research paper).. And if the indian book has been written for IITJEE,then it is almost definitely certain that it can never be correct against a foreign author

Always keep this in mind

Like,to keep it as a measure,the polarisation caused by 2 cations,like Cu+ and Li+ in R2CuLi,starts the softness which is enough to cause 1,4 addition

@Fancy-Toon Yep,gasesos

And if your reference is cengage,then i am sorry,but clayden trumps cengage always

So, in short Cengage is wrong when it states that G.R reacts with a,b unsaturated carbonyl compounds via 1-4 addition..though it goes on to say that if the double bond is sterically hindered, then 1,2 addition product is formed in major amount...

@YusufHasan I just follow it because I've to study things relevant to JEE advanced, and it particularly prioritizes them.. thanks for ur time and knowledge

@Jasmine How did it go?

@Fancy-Toon Yep,basically what @RafaelNadal gas said is correct; RLi looks to add to the C=O as per HSAB,but in case that position is extremely hindered,it has to make do with the 1,4 position(which is not as hard as the carbonyl carbon,but still,due to the extended resonance leading to a partially positive carbon,it can work as a 2nd choice when 1st preference isn't available

@YusufHasan: Hi. If possible, could you please help me regarding the following question? Thanks!

It's not a homework type, but I don't know the reason for the downvotes.