D & L Glucose: Haworth Formula Explained

  • Thread starter Thread starter gracy
  • Start date Start date
  • Tags Tags
    Convention
AI Thread Summary
The discussion centers on the representation of D-glucose in the Haworth formula, specifically addressing a perceived inconsistency regarding the orientation of the penultimate carbon (C5). The confusion arises from the claim that both structures represent D-glucose despite C5 having a hydrogen atom on the right side instead of a hydroxyl group, which traditionally indicates L-glucose. The explanation provided involves the concept of bond rotation around the C4-C5 axis, allowing for rapid adjustments in molecular conformation without altering stereochemistry. This flexibility is likened to a tripod, helping to visualize the molecular structure. Additionally, there is a shared sentiment regarding the complexity of the D/L nomenclature, with some expressing frustration over its retention and understanding.
gracy
Messages
2,486
Reaction score
83
Chemistry news on Phys.org
It is a rotation around the axis defined by the C4-C5 bond by 60°. Bonds are allowed to rotate, and do so very quickly without changing stereochemistry. Imagine the three substituents on C5 as the legs of a tripod, with the camera or whatnot as the rest of the molecule, and you may be able to see it better.

Refer to this link for an idea about D/L. For what it's worth, I agree with that author about the whole D/L convention. It always annoyed me and I never retained that information beyond whatever exam I needed to know it for.
 
I want to test a humidity sensor with one or more saturated salt solutions. The table salt that I have on hand contains one of two anticaking agents, calcium silicate or sodium aluminosilicate. Will the presence of either of these additives (or iodine for that matter) significantly affect the equilibrium humidity? I searched and all the how-to-do-it guides did not address this question. One research paper I found reported that at 1.5% w/w calcium silicate increased the deliquescent point by...
I was introduced to the Octet Rule recently and make me wonder, why does 8 valence electrons or a full p orbital always make an element inert? What is so special with a full p orbital? Like take Calcium for an example, its outer orbital is filled but its only the s orbital thats filled so its still reactive not so much as the Alkaline metals but still pretty reactive. Can someone explain it to me? Thanks!!
I'm trying to find a cheap DIY method to etch holes of various shapes through 0.3mm Aluminium sheet using 5-10% Sodium Hydroxide. The idea is to apply a resist to the Aluminium then selectively ablate it off using a diode laser cutter and then dissolve away the Aluminium using Sodium Hydroxide. By cheap I mean resists costing say £20 in small quantities. The Internet has suggested various resists to try including... Enamel paint (only survived seconds in the NaOH!) Acrylic paint (only...
Back
Top