Comments on: How To Determine R and S Configurations On A Fischer Projection https://www.masterorganicchemistry.com/2019/05/21/how-to-determine-r-and-s-configurations-on-a-fischer-projection/ Sat, 18 Apr 2026 10:05:13 +0000 hourly 1 https://wordpress.org/?v=6.9.4 By: James Ashenhurst https://www.masterorganicchemistry.com/2019/05/21/how-to-determine-r-and-s-configurations-on-a-fischer-projection/#comment-731820 Wed, 26 Mar 2025 14:31:51 +0000 https://www.masterorganicchemistry.com/?p=12435#comment-731820 In reply to Ryan P Cohen.

If I understand your question correctly, that’s if you *rotate* the whole molecule analogous to the way that a person sleeping on their back rotates on to their left shoulder.

]]> By: Ryan P Cohen https://www.masterorganicchemistry.com/2019/05/21/how-to-determine-r-and-s-configurations-on-a-fischer-projection/#comment-730779 Wed, 19 Mar 2025 08:16:54 +0000 https://www.masterorganicchemistry.com/?p=12435#comment-730779 Why is the left side depicted as the back and right side is the front, if both are wedges and are facing you in a fisher projections aren’t they both the front

]]> By: Adewuyi Fatimoh https://www.masterorganicchemistry.com/2019/05/21/how-to-determine-r-and-s-configurations-on-a-fischer-projection/#comment-722828 Wed, 08 Jan 2025 02:44:10 +0000 https://www.masterorganicchemistry.com/?p=12435#comment-722828 Thanks you very much sir I found this very helpful and the topic is very understandable

]]> By: James Ashenhurst https://www.masterorganicchemistry.com/2019/05/21/how-to-determine-r-and-s-configurations-on-a-fischer-projection/#comment-648613 Tue, 21 Feb 2023 16:56:01 +0000 https://www.masterorganicchemistry.com/?p=12435#comment-648613 In reply to Ajeeb.

Use the same method as for a single chiral center. There is no special extra technique required for multiple chiral centers.

]]> By: Ajeeb https://www.masterorganicchemistry.com/2019/05/21/how-to-determine-r-and-s-configurations-on-a-fischer-projection/#comment-648483 Sun, 19 Feb 2023 15:38:13 +0000 https://www.masterorganicchemistry.com/?p=12435#comment-648483 Sir How can we name a Fischer projection with three chiral centres?

]]> By: Harshwardhan https://www.masterorganicchemistry.com/2019/05/21/how-to-determine-r-and-s-configurations-on-a-fischer-projection/#comment-644205 Mon, 12 Dec 2022 18:59:35 +0000 https://www.masterorganicchemistry.com/?p=12435#comment-644205 Very useful and good information through jee point of view . Waiting for more concepts.

]]> By: James https://www.masterorganicchemistry.com/2019/05/21/how-to-determine-r-and-s-configurations-on-a-fischer-projection/#comment-640015 Tue, 11 Oct 2022 07:02:23 +0000 https://www.masterorganicchemistry.com/?p=12435#comment-640015 The site is helpful and can’t wait to thank you. Glad to learn chemistry from you.

]]> By: James Ashenhurst https://www.masterorganicchemistry.com/2019/05/21/how-to-determine-r-and-s-configurations-on-a-fischer-projection/#comment-639486 Tue, 04 Oct 2022 17:22:23 +0000 https://www.masterorganicchemistry.com/?p=12435#comment-639486 In reply to amirrr.

Generally R/S is defined according to the point of first difference. Since the carbon would be the point of first difference, 14CH3 would take priority over 12CD3. it would take priority.

]]> By: amirrr https://www.masterorganicchemistry.com/2019/05/21/how-to-determine-r-and-s-configurations-on-a-fischer-projection/#comment-639357 Sun, 02 Oct 2022 09:06:23 +0000 https://www.masterorganicchemistry.com/?p=12435#comment-639357 hello sir.
could you please determine the prioritize of the structure in the link? for example CD3 is the first priority or 14CH3 is the first? please arrange them for me. tnx
i asked this problem to some ppl. but they answered me different .
link of the image:
https://www.mediafire.com/file/04befcfzsoh04nt/Screenshot+(565).png/file

]]> By: James Ashenhurst https://www.masterorganicchemistry.com/2019/05/21/how-to-determine-r-and-s-configurations-on-a-fischer-projection/#comment-630821 Mon, 20 Jun 2022 17:54:21 +0000 https://www.masterorganicchemistry.com/?p=12435#comment-630821 In reply to Sadegh.

Yes, the big case is when you do a bond rotation on the bottom-most carbon such that an H is pointing straight down. In that case the #4 substituent (the H) is actually pointing in the back, such that the “reverse rules” don’t apply

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