NOMENCLATURE
WORDS ABOUT WORDS AUSTIN M. PATTERSON* ACS Committees, Concluded T h e Committee on t h e Nomenclature and Symbols of Physical Chemistry, of the ACS Division of Physical a n d Inorganic Chemistry, was organized in 1947. It con sists of T. F . Young ( D e p a r t m e n t of C h e m istry, University of Chicago, Chicago 37, 111.), chairman; Roy F . Newton and J. W . Williams. Its work is closely interwoven with that of the Subcommittee on Physicochemical Symbols a n d Terminology of the National Research Council a n d will be treated later u n d e r t h e latter heading, since the reports have been issued u n d e r t h e NRC label. The Committee on Nomenclature, of the ACS Division of Analytical Chemistry, has for some time been a t work on a series of definitions of analytical terms, which is approaching final form. Its chairman is L. T. Hallett (General Aniline and Film Corp., Coal and Lincoln Sts., Easton, P a . ) and its other members are S. E . Q. Ashley, H. V. Churchill, H. C. Diehl, N. H. Furman, and R. P. G r a h a m .
Commission Decisions !n New York Last month in New York t h e I U P A C nomenclature commissions h a d to hold their sessions w h e n and how they could. T h e International Union was sandwiched in between the ACS Jubilee a n d the In ternational Congress a n d was allotted only two days. T h e Commission on t h e Codifi cation, Ciphering, and Classification of Organic Compounds m e t jointly with J. W . Perry's ACS Committee on Mechanical Aids to Literature Searching, in Cam bridge at M I T , Aug. 27 to 3 1 . The Com mission, under the chairmanship of P. E. Verkade, has been studying n i n e different codes for the " s h o r t h a n d " linear represen tation of the structures of organic com pounds. To give an idea of t h e nature of these codes let us take the "ciphers" for a faidy simple compound, C H 3 C H O H C B r : C B r C H O H C H 3 ( 3,4-dibromo-3-hexene-2,5diol): Dyson: C6.E,3.Q,2,5.Br,3,4. G-K-D: ffONfJ^CTr^aMTOH1. Gruber: C 6 . 3 = . 2 , 5 0 H . 3 . 4 B r . Newcastle: 2 0 H l B r : I B r l O H l . NRC: H 8 D . 2 - L 4 7 . 2 - 0 6 Y . 1 . Silk: C Q C Q C . van W e e r d e n : 2-32.02-314.02-22-16. Wiselogle: 02-2 a l e ; Br-5 bromo deriv.; double bon'd. VViswesser: .QY.YEYEY.Q. G-K-D stands for Gordon-KendallDavison. All nine codes, w i t h a large n u m b e r of examples from each, have been studied impartially. T h e National Research Council, van W e e r d e n and Wiselogle codes are felt to be useful for special pur poses b u t not to b e of the general type
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which the Commission h a s in m i n d . P r o ponents of the Dyson, Gruber, a n d VVis wesser codes were present to explain t h e i r systems a'nd answer questions. After p r o longed discussion the group finally, by nearly unanimous vote, r e c o m m e n d e d to the Commission that the Dyson system be used as a basis for t h e code which the Commission will finally adopt. It is agreed that the Dyson code can be improved, and the good points of the o t h e r codes will be carefully studied. T h e Dyson system is the oldest a n d best known of the nine. It was first an nounced b y G. Malcolm Dyson in 1946. He published a description of it in 1947, revised in 1949 ( "A N e w Notation and Enumeration System for Organic C o m p o u n d s , " ed. 2, L o n g m a n s ) . An interest ing feature of the Dyson code is t h a t it lends itself Avell to translation into a n a m e for each compound which is not radically different from o u r present systematic names except in t h e case of complex r i n g compounds. Thus, in t h e Dyson cipher given above, C6 can be translated "hex," Ε " e n e , " Q "ol," etc. a n d the correspond ing name can b e hexene-3-diol-2,5-dibromo-3,4. Methods for using t h e Dyson code with punched cards are being worked out. T h e Commission on Organic Nomencla ture began its sessions Sept. 1. I t m a d e a few minor corrections a n d changes in the list of radical names published in the Comptes Rendus of the Amsterdam L949 Conference ( p . 1 3 2 ) . "Methallyl" "was dropped in favor of "E-methylallyl." "Tosyl" was restricted to the p a r a c o m p o u n d ( a n d even there p-tolylsulfonyl or p-toluenesulfonyl is preferred). The ex ceptions to the oyl rule for acid radicals ( 5 8 . 3 ) were supplemented; they now in clude formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, oxalyl, rnalonyl, succinyl, and glutaryl. " H e x a n o y l " replaces "caproyl." "Acetoxy" is now p r e ferred to "acetyloxy" instead of vice versa. "Anisoyl" is no longer limited to the p a r a compound; it should have o, m or ρ p r e fixed. "Isopropenyl," "isopropylidene" a n d " m e r c a p t o " are to b e used for t h e u n s u b scituted radicals only. " T h i o n o " (and not "thioxo") is to be used to denote replace ment of H 2 (attached t o same a t o m ) b y S as well as replacement of 0 = by S . T h e following wording was a d o p t e d for the rule on indicated hydrogen (formerly called "extra hydrogen" ) : " W h e n a n a m e applies equally well to two or more iso meric monocyclic o r condensed ring sys tems of t h e lowest possible stage of hy drogénation, and when t h e n a m e can b e m a d e specific by indicating t h e position of one or more hydrogen atoms in the structure, this m a y be accomplished, b y modifying the n a m e with a position s y m bol, followed by italic capital H , for e a c h
CHEMICAL
such atom. Such symbols will ordinarily p r e c e d e t h e n a m e . T h e said atom or a t o m s may b e called 'indicated hydrogen'/* 3HFluorene and 2H-pyran-4-yl are t w o of t h e examples given. I t will be n o t e d that this rule applies to cyclic compounds only; application of the H n a m e s to open c h a i n s is still u n d e r consideration. The above rule a n d also the rules on radical n a m e s a n d on organosilicon compounds (Amsterd a m Comptes R e n d u s , p . 127) Avère adopted definitively; those on aliphatic cis and trans isomers [C&EN, 26, 2959 ( 1 9 4 8 ) 1 and on application of t h e " a " nomenclature to heterocycles (revision of I U C rule 16) are still on a tentative basis. T h e Organic Commission has adopted t h e following principles as a g u i d e for future deliberations: 1. W h e r e v e r feasible, systematic n o m e n clature should be u s e d for aliphatic comp o u n d s containing six or more c a r b o n atoms. 2. It is desirable to have the s a m e principles and conventions apply to both t h e future cipher a n d t h e future n o m e n c l a ture. 3. I t w o u l d b e b e t t e r to search for an entirely n e w or even revolutionary nomenclature for polycyclic ring systems t h a n to spend time a n d effort in a t t e m p t i n g to extend or revise existing systems. T h e Commission already has o n its a g e n d a for t h e future, 11 items which it has apportioned to its members for study. T h e E u r o p e a n m e m b e r s plan to hold an interim meeting next summer. Des- or De-? N a m e s like desoxybenzoin and desoxycholic acid h a v e b e c o m e fairly common, a n d the use of des- h a s even been extended to form such names as desthiobiotin and desstrychnidine. T h e s e names are not good English. They w e r e apparently taken over ( in the beginning, at any rate ) from G e r m a n and French, w h e r e des- has good standing. T h e correct English prefix is deana not des-. W e d o not say desoxidize, deshydrate, d e s n a t u r e , or desfrost. W h y , then, should w e allow our organic chemical n a m e s to depart from good general E n g lish usage? Des- should be replaced by d e - in all such cases; as, for example, d e oxycholic. T h e L o n d o n Chemical Society uses deoxy- ( as a contraction of dehydroxy-) to m e a n replacement o f O H b y H , a n d deoxo- to m e a n replacement of Ο b y H 2 . If you are interested in etymol ogy, des- comes from Old French, w h i c h in t u r n took it from L a t i n dis-. D e - comes to us through the F r e n c h , unchanged from t h e original Latin.
T h e address of chairman Biegel o f the Subcommittee on Steroids, National Re search Council, has b e e n changed t o : By ron Riegel, G. D. Searle and Co., P . O . Box 5 1 1 0 , Chicago 80, 111. J. J. Bikerman, w h o has been a mem b e r of t h e C o m m i t t e e on Nomenclature, ACS Division of O r g a n i c Chemistry, since its organization, has resigned. A. H. C u b berley is a n e w m e m b e r . « 2 2 1 North King St., Xenia, Ohio.
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