Historical significance

Common names, chemical stmcture, and synonyms for the vitamins are given in Table 3. The names given to the vitamins and/or their letter designations do not foUow a logical pattern and are of historical significance only. Despite this, the nomenclature is in common use. 

Parentheses indicate minor processes primarily of historical significance. 

These have only a historical significance, in the light of better defined enclosures now available. They are briefly defined here ... 

With the exception of some of the natural rubber derivatives these materials were available during the first deeade of this eentury and, together with celluloid, aetually completed the range of plastics materials then in eommercial use. In spite of being ousted from important markets they have continued to find use in specialised applications, details of which will be given in subsequent sections of this chapter. The historical significance of these materials was dealt with in the first chapter of this book. 

The following paper is of great historical significance in the field. 

Table 3.2 records historically significant calculations for the electronic ground state of H2+. 

An additional impetus for the development of biomimetic polyolefinic cyclizations was provided by the historically significant Stork-Eschenmoser hypothesis,4 a postulate that rationalizes the... 

The first total synthesis of erythronolide B (1) by Corey stands as an event of great historical significance in synthetic chemistry it provides a powerful illustration of the utility of Corey s methods of macrolactonization and it demonstrates, in a particularly insightful way, the value of using readily accessible six-membered ring templates for the assembly of contiguous arrays of stereo-genic centers. 

In 1967 Agtarap et al. disclosed the isolation and structure of monensic acid (1).3 Compound 1, now known as monensin, is produced by a strain of Streptomyces cinamonensis, and exhibits broad-spectrum anticoccidial activity. Since its introduction on the market in 1971, monensin has been used very successfully to combat coccidial infections in poultry and as an additive in cattle feed.4 In the polyether family, monensin occupies a position of some historical significance. Although monensin was the fifth polyether... 

The ring expansions of cydohexadiene derivatives to azepines is of historical significance, as the first example of a monocyclic 1//-azepine was obtained by cyanide ion attack on 2-acetoxy-2,4,6-trimethyl-iV-(phenylsulfonyl)cyclohexa-3,5-dien-l-imine (4) 17 however, it was almost twenty years before the product was correctly formulated as the l//-azepine 5.24... 

A system was developed at Roche Laboratories whereby a sheet (or web ) was coated with a drug/binder mixture. The solid dosage units were then punched from the web [168]. This system was very flexible and amenable to immediate release and sustained-release technologies. However, due to the im-practicality of the system, it was abandonned in the mid-1980s and is only of historical significance. 

Another organic compound of arsenic that is of historical significance was discovered in 1901 by P. Ehrlich. That compound is known as arsphenamine or Salvarsan, which has the structure... 

The structure of [Ti(OEt) , ] , reported by Ibers (2) in 1963 was of historic significance since it provided the first structural test of Bradley s theory for a compound of formula M(OR)h. Each titanium atom achieves an octahedral environment, through the agency of four doubly bridging and two triply bridging alkoxy groups, as is shown in II. 

As in prior chapters, we review historically significant approaches toward C-P bond formation, noting the advantages and disadvantages of classical approaches, contemplate the more recent advances, and consider the opportunities associated with each. Detailed experimental procedures for examples of each of the types of reactions are provided. 

Table 7.2 Reactive systems of minor or historical significance only... 

The manual separation of the enantiomorphous crystals of sodium ammonium tartrate tetrahydrate (Figure 1) by Pasteur in 1848 (1) is historically significant, because it laid the foundations of modem stereochemistry. This experiment demonstrated for the first time that certain classes of molecules display enan-tiomorphism even when dissolved in solvent. These observations eventually paved the way for the inspired suggestion, made more than two decades later, by van t Hoff (2) and Le Bel (3), of a tetrahedral arrangement of bonds around the carbon atom. 

Ultrasonic cleaning is another major application for power ultrasound. It is now such a well-established technique that laboratories without access to an ultrasonic cleaning bath are in a minority. It is important to recognise the historical significance of the development of ultrasonic cleaning technology on the growth of sonochemistry because, in the early years, the humble laboratory cleaner was almost certainly the first ultrasonic apparatus used by chemists. 

Poison-hemlock also has historical significance to researchers because coniine was the first alkaloid discovered, in 1827, and was first synthesized in 1886 (Landenburg, 1886, reviewed in Panter and Keeler, 1989). 

Autism (Pervasive Development Disorder). The association between schizophrenia and autism is of particular historic significance. Bleuler, who coined the term schizophrenia, included autism as one of his four As among the symptoms of schizophrenia, the others being affect, ambivalence, and association. By autism, Bleuler meant the indifference to and separation from normal social interaction that is characteristic of schizophrenia. 

The investigation committee method is another unsuccessful approach. This unstructured approach is historically significant and was judged inadequate for investigating process safety incidents because it produced incomplete and inconsistent results. It often did not find the root cause level or all the root causes. 

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