Iso amygdalin and the resolution of its hepta-acetyl derivative / by Frank Tutin.
- Tutin, Frank.
- Date:
- [1909?]
Licence: In copyright
Credit: Iso amygdalin and the resolution of its hepta-acetyl derivative / by Frank Tutin. Source: Wellcome Collection.
6/10 page 666
![Acetylation of \§o Amygdalin. Separation of Hepta-acetylamygdalin. A few grams of amygdalin were dissolved in water, a little ammonia added, and the mixture allowed to stand overnight. The solution was then evaporated on the water-bath to a syrup, and the residue boiled for a short time with a large excess of acetic anhydride, a trace of c£-camphorsulphonic acid having been added. After concentrating the solution to a small bulk, it was diluted with ether and cooled. As crystallisation did not begin quickly, this was initiated by means of a trace of hepta-acetylamygdalin. After about three hours the crystals were collected and washed with ether, when they melted at 159—160°. The yield was about 20 per cent, of that theoretically possible : 0*3400, made up to 20 c.c. with chloroform, gave aD - 1°24' in a 2-dcm. tube, whence [a]D -41*2°. After three crystallisations from alcohol the material melted at 166—167°, and was evidently pure hepta-acetylamygdalin, since the melting point was not lowered on mixing with an authentic specimen of the latter. A determination of the specific rotatory power gave the the following result: 0*4030, made up to 20 c.c. with chloroform, gave aD — 1°3T in a 2-dcm. tube, whence [a]D -37*6°. The above experiments were repeated several times, and were always attended with a similar result. Separation of Hepta-acetylneoamygdalin. Twenty grams of amygdalin were converted into isoamygdalin by means of ammonia, and the product acetylated as described above. After removing the greater part of the anhydride by distillation, some alcohol was added, and the mixture largely diluted with ether. The solution was then brought into a separator and washed with water, when, as the alcohol was removed, a quantity of heavy, oily material was deposited from the ether, and was separated with the water. This oil became solid on standing, but the greater part of it could not be crystallised ; some hepta-acetylamygdalin was, however, separated from it. On keeping the ethereal solution overnight, a quantity (about 9 grams) of crystalline material separated. This was recrystallised from alcohol, after which it melted at 168—172°, but when mixed with hepta-acetylamygdalin fusion occurred at 155—158°. The substance was evidently fully acetylated, for it was not changed by prolonged treatment with acetic anhydride : 0*4027, made up to 20 c.c. with chloroform, gave — 2°34' in a 2-dcm. tube, whence [a]D - 63*7°,](https://iiif.wellcomecollection.org/image/b30614405_0006.jp2/full/800%2C/0/default.jpg)
