Sciencemadness Discussion Board

Synthesis of Ascorbic Acid

soma - 14-9-2017 at 00:27

I read that the "Osone - Cyanide" method of synthesis of ascorbic acid is the best and simplest.
Quote:
Conversion of sugars into the corresponding osones is readily brought about by the wtiori of alcoholic cupric acetate.
Without further purification, these osones may be converted into ascorbic acids by condensation with potassium cyanide
followed by hydrolysis with dilute mineral acid. If carried out at 95" rather than 45-50' as formerly prescribed the hydrolysis
can be completed in 3 hours instead of 1-2 days.

-- Synthesis of Ascorbic Acids by the Osone—Cyanide Method1
J. Kelvin Hamilton, F. Smith
J. Am. Chem. Soc., 1952, 74 (20), pp 5162–5163


Opinions?



Sulaiman - 14-9-2017 at 06:40

The obvious question;

If the salicylic acid (or derivatives such as wintergreen) is intended for use on sentient beings,
can you be certain that no cyanide(s) will end up in your final product ?

soma - 15-9-2017 at 00:20

Ascorbic acid = vitamin C.

Many plants contain small amounts of cyanide. E.g. types of bean sprouts, carrots, celery, wheatgrass, yams, brown rice, butter beans, lima beans and mung beans.

(They contain amygdalin which releases cyanide in contact with acid.)

XeonTheMGPony - 15-9-2017 at 07:04

Don't forget peach pits and apple seeds.

soma - 16-9-2017 at 01:19

And, of course, apricot kernels.

[Edited on 16-9-2017 by soma]

unionised - 16-9-2017 at 08:22

Since the product is an acid any cyanide present would be converted to HCN (which is a very weak acid) and would be lost by evaporation.

The person doing the synthesis might kill them self, but the final product would be relatively safe.