scholarly journals Optically Active Di- and Tetra-methyl-spiro-5 : 5-Dihydantoins

1936 ◽  
Vol 155 (884) ◽  
pp. 1-11
Author(s):  
William Jackson Pope ◽  
James Bell Whiteworth
Keyword(s):  
Optical Activity ◽  
Methyl Alcohol ◽  
Active Form ◽  
Rotatory Power ◽  
Alcoholic Solution ◽  
Optically Active ◽  
Active Components ◽  
Molecular Configuration ◽  
Enolic Form ◽  
Soda Solution

In a previous paper* we described the resolution into optically active components of the spiro -5: 5-dihydantoin 7 6 1 2 NH—CO—C—NH—CO ∣ ∣ CO—NH—C— CO-NH 8 9 4 3 prepared by Biltz, Heyn, and Bergius; these compounds are probably the simplest optically active spiranes which can be obtained and may therefore be regarded as the type case of optical activity associated with one particular kind of molecular configuration. We also adduced evidence, based on the different rotatory dispersions shown by the optically active dihydantoins in absence and presence of alkali, indicating that these substances could assume three tautomeric forms. This work has now been extended to the study of the optically active 3: 7-dimethyl- spiro -5: 5-dihydantoins and their acidyl derivatives and tetramethyl- spiro -5: 5-dihydantoins. Tetramethyldihydantoin, which can only exist in the ketonic state, gives, in methyl alcohol, a rotatory dis-persion curve of the simple form, with λ 0 = 2478 A, nearly congruent with that of the unsubstituted dihydantoin in alcoholic solution with λ 0 = 2453 A. This is a further indication that in neutral solvents and pyridine the dihydantoin has the ketonic form. The 3: 7-dimethyl- dihydantoin also shows normal rotatory dispersion in methyl alcohol and the curve, with λ 0 = 2381 A, is nearly congruent with those just quoted; it should therefore be of the ketonic form in neutral solvents. The initial rotatory power of this compound in dilute soda solution is only about one-seventh of that in alcohol; passage to a tautomeric enolic form is thus indicated. The specific rotatory power in soda solution rapidly falls, however, to —1-6° for λ = 5461, a value which persists for some time; the falling off in rotatory power is due to hydrolysis with formation of 3: 8-dimethylallantoin, CH3 . NH . CO . NH . CH—NH . CO ∣ CO . N . CH 3 Although this compound was only isolated from the soda solution in an optically inactive form, it would seem to exist in the optically active form in the cold soda solution. This result is of interest in connexion with recent work on the optical activity of allantoin itself.*

scholarly journals The symmetrical spiro -heptanediamine and its resolution into optically active components

1936 ◽  
Vol 154 (881) ◽  
pp. 53-60 ◽  
Keyword(s):  
Carbon Atom ◽  
Optical Activity ◽  
Optically Active ◽  
Active Components ◽  
Asymmetric Carbon Atom ◽  
Molecular Configuration ◽  
Experimental Realization ◽  
Asymmetric Carbon ◽  
Acetic Acids

The experimental realization of the simplest possible types of molecular configuration which can show optical activity in the amorphous con­dition is important in connexion with stereochemical theory. Among optically active spiranes containing no asymmetric carbon atom such simple types are found in the d - and l -1-methyl- cyclo -hexylidene-4-acetic acids and the d - and 1-spiro- 5:5-dihydantoins, but no satisfactory case has hitherto been described of optical activity in substances of the constitution H —C—( CH 2 ) n —C—(CH 2 ) n —X X —C—( CH 2 ) n —C—(CH 2 ) n —H. One of the simplest conceivable examples of the latter kind should be found in the previously unknown symmetrical spiro -heptanediamine of the constitution— NH 2 —C—CH 2 —C—CH 2 —C—H H—C—CH 2 —C—CH 2 —C—NH 2 .

scholarly journals The optically active spiro-5:5-Dihydantoins

1931 ◽  
Vol 134 (824) ◽  
pp. 357-371 ◽  
Keyword(s):  
Optical Activity ◽  
Amorphous State ◽  
Optically Active ◽  
Cooh Cooh ◽  
Tetracarboxylic Acid ◽  
Synthetic Material ◽  
Active Components ◽  
Synthetic Compound ◽  
First Case

The first substance to be obtained, showing optical activity in the amorphous state but containing no asymmetric atom in the molecule, was the 1-methyl cyclo hexylideneacetic acid, CH 3 /CCH 2 . CH 2 C = CH H/ CH 2 . CH 2 / COOH of Perkin and Pope, the resolution of the synthetic material being effected by Perkin, Pope and Wallach. In a later paper Perkin and Pope showed that the optical activity persists in a remarkable way throughout a series of reactions. At that time it was recognised that certain types of carbospiranes should be similarly resolvable into optically active components, but the first case of this kind to be realised was that of the keto-dilactone of benzophenone- 2 :4 :2 ': 4'-tetracarboxylic acid prepared by Mills /CO_O COOH/¯¯\__|__/¯¯ COOH ; C \__/ \__/ |O-CO/ the resolution was effected by Mills and Nodder. The work of Mills and Nodder established the stereochemical principle involved, but the compounds used in this and similar later investigations are of complex constitution and do not lend themselves readily to the study of the effects of substitution or tautomeric change on the optical activity. We consequently prepared the spiro -5: 5-dihydantoin described by H. Biltz, Heyn and Bergius, and succeeded in resolving the synthetic compound into its optically active components by crystallisation with brucine.

On the theory of optical activity III-A regular tetrahedron twisted through a small angle about a binary axis

1936 ◽  
Vol 153 (879) ◽  
pp. 339-352 ◽  
Keyword(s):  
Optical Activity ◽  
Small Angle ◽  
Order Approximation ◽  
Rotatory Power ◽  
Optically Active ◽  
Regular Tetrahedron ◽  
The Third ◽  
Small Coupling ◽  
Zero Order Approximation ◽  
Regular Shape

The problem of optical activity of a molecule, which is built up of several groups to each of which is attributed an isotropic resonator, has been treated by Born* in a paper with the same title (Part I and II). The method of approximation used there depends on the assumption of small coupling forces, i. e., large distances between the resonators. It seems of some interest to investigate whether active models can he found which may be treated without this assumption of large distances. A regular tetrahedron, the corners of which carry identical isotropic resonators, is not optically active. If, however, changes of shape and therefore of mechanical property are introduced which exclude a plane of symmetry, the system can be optically active. In this paper we consider a change brought about by a small twist of the regular shape of the tetrahedron. Two of the corner of the regular tetrahedron are kept fixed and the other two are rotated through a small angle, along a binary axis connecting the centres of the two edges. Such a system has evidently no plane of symmetry and it can be optically active.* The rotatory power can be calculated by a method of approximation. In this the regular tetrahedron is taken as the zero order approximation. We shall show that the optical activity is proportional to the third power of the small angle of twist.

Optical analysis of ink and other contaminants in process waters

TAPPI Journal ◽  
2012 ◽  
Vol 11 (8) ◽  
pp. 51-58
Author(s):  
ANTTI HAAPALA ◽  
MIKA KÖRKKÖ ◽  
ELISA KOIVURANTA ◽  
JOUKO NIINIMÄKI
Keyword(s):  
Optically Active ◽  
Process Water ◽  
Paper Machine ◽  
Optical Analysis ◽  
Direct Process ◽  
Active Components ◽  
Water Contaminants ◽  
Dependent Measurement ◽  
Measurement Methodology

Analysis methods developed specifically to determine the presence of ink and other optically active components in paper machine white waters or other process effluents are not available. It is generally more interest¬ing to quantify the effect of circulation water contaminants on end products. This study compares optical techniques to quantify the dirt in process water by two methods for test media preparation and measurement: direct process water filtration on a membrane foil and low-grammage sheet formation. The results show that ink content values obtained from various analyses cannot be directly compared because of fundamental issues involving test media preparation and the varied methodologies used to formulate the results, which may be based on different sets of assumptions. The use of brightness, luminosity, and reflectance and the role of scattering measurements as a part of ink content analysis are discussed, along with fine materials retention and measurement media selection. The study concludes with practical tips for case-dependent measurement methodology selection.

On the syntheses and the optical properties of optically active 2-pyrazoline compounds

1979 ◽  
Vol 57 (3) ◽  
pp. 360-366 ◽  
Author(s):  
Makoto Mukai ◽  
Takashi Miura ◽  
Masahiro Nanbu ◽  
Toshinobu Yoneda ◽  
Yohji Shindo
Keyword(s):  
Optical Properties ◽  
Optical Activity ◽  
Optically Active ◽  
Spectroscopic Techniques ◽  
Considerable Influence ◽  
Pyrazoline Ring

Optically active 2-pyrazolines were synthesized and their optical properties were studied using various spectroscopic techniques to investigate the effects of substituents at the 3 and 5 positions of the 2-pyrazoline ring on their optical activity. It was found that in the case of 5-substituted-1,3-diphenyl-2-pyrazoline derivatives, the substituent at the 5 position has considerable influence on the optical activity, whereas in 3-substituted-1,5-diphenyl-2-pyrazoline derivatives, the substituent at the 3 position has no such influence.

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