NOMENCLATURE
WORDS ABOUT WORDS AUSTIN M. PATTERSON* Proposed Revision of Terpene Nomenclature: A P r e v i e w Soon after the Committee on Nomenclature of the ACS Division of Organic Chemistry was organized in 1946, i t set up a subcommittee on the nomenclature of terpenes, headed by Mildred W . Grafflin of the research department, Hercules Powder Co., Wilmington, D e l . The subcommittee has consulted leading terpene chemists such a s Dupont of France, Simonsen of England, Toivonen of Finland, and Goldblatt and Hasselstrom in this country, and also other organic chemists. T h e terpene compounds could all be named with strict systematic terminology, but these names w o u l d often be long •and unsuitable, except for special purposes. On the other b a n d many of the trivial terpene names are misleading or conflicting and a t best they place a burden on the memory. The subcommittee has tried to steer a middle course, retaining many of the well-known names and preserving the terpene "flavor" of the present terminology but introducing more system. Such a revision should have the advantage not only of providing clearer names but of better bringing out the relations between compounds. Judging
from t h e comments of consultants the work is succeeding splendidly. It has not yet reached the final stage, however, and Miss Grafflin welcomes comments and suggestions. The proposed general scheme is based on reducing the chemical structures to a f e w fundamental types and assigning fixed numberings to their carbon skeletons. Acyclic Terpenes The acyclic terpenes can be readily systematized by naming t h e m like other ethylenic hydrocarbons ( International Union r u l e s ) . Trivial names like ocimene and myrcene will still be convenient. Monocyclic Terpenes T Y P B A. Derivatives of menthane. For these t h e convenient merrth- names used b y Wagner and Wallach and the wellestablished numbering scheme shown in I are used. For example, dipentene may b e called 1,8-p-menthadiene. In I only the para form of menthane is shown but the system i s applied equally to the ortho and meta forms. T Y P E B. Other monocyclic terpenes. Here t h e important skeletons are III ( cyclogeraniolenes) and IV ("pyronenes").
The idea is being considered of naming the series II, III, IV dimecane, trimecane and tetramecane (contractions of dimethyl-, trimethyl- and tetramethylcyclohexane). Thus "a-pyronene" would b e 3,5-tetramecadiene; the full systematic name is l,5,5,6-tetramethyl-l,3-cyclohexadiene. Isomeric "mecane" parents could be distinguished b y numerals, but t h e forms would probably b e limited to those containing gem-dimethyl. However, t h e scheme is still quite tentative. Bicyclic Terpenes T h e bicyclic type compounds are thujane ( V ) , carane ( V I ) , pinane ( V I I ) , bornane ( V I I I ) , fenchane ( I X ) , and santane ( X ) . The parent of borneol and camphor ( V I I I ) , is called bornane rather than camphane because of conflicting names beginning with camph-. Corresponding to these six types are the fourparent ring systems northujane (bicyclo[3.1.0]hexane, X I ) , norcarane (bicyclo[4.1.0]heptane, X I I ) , norpinane (bicyclo[3.1.1]heptane, X I I I ) , and norbornane (bicyclo[2.2.1]heptane, X I V ) . It should be noted that in figures V to XIV t h e bicyclo numbering is followed for t h e parent ring system, but in V to X t h e numbers of the side chains are fixed and
"VTTT
Rubber Lined Equipment Important t o you is the complete control Arco exercises over every stage of production from compounding of the rubber specifically for your job to installation o f the equipment. This is assurance o f quality and satisfaction. Write for our catalog.
ri!iiiTnouiii*di]iiiiiJCEM]^ Sf8:Mîl|lMEÏEF^Ca^
930
C H E M I C A L
΀fc 4 ~ '9
IK
ŒP n 4
I
X
XC
m rx m :Φ ι
7
6
5
XŒ
xm
AND
ENGINEERING
4
Xl\/ NEWS
do not change w h e n double bonds or functional groups are present. One matter that is troubling the sub committee is whether it is ever advisable to name a compound having a certain carbon skeleton with side chains as the derivative of one having another skeleton with side chains; for example, could IV be named as a derivative of III and called 2^methyltrimecane? Such names are often shorter (for instance, instead of 2,6,6trimethyl-4-methylenenorpinane one could use 4-methylenepinane ) but they open up possibilities for trouble. The subcommit tee is making tests to see whether they should be avoided. In keeping with terpene usage the prefix nor- is applied to the stripping off of all side chains and not, as in the steroid field, to the removal of merely one CH 2 ; for the latter purpose apo- is pro posed; f o i example, apofenchane desig nates fenchane ( I X ) from which the methyl group numbered 10 (at position 1) is replaced by hydrogen, numbers 8 and 9 remaining as in fenchane. Similarly, apobornane is bornane (VIII) minus the 10 methyl group. W h e n names for the saturated hydro carbons have been agreed upon those for the corresponding unsaturated compounds can b e handled b y use of the endings -ene and -diene, with numerals to indicate the positions of the double bonds, in the usual fashion. Thus the system name for α-pinene is 2-pinene and that for j8-pinene is 2 ( 1 0 ) - p i n e n e . The naming of deriva tives has been kept constantly in mind; they can b e treated in the customary w a y by prefixes and suffixes; as, 1-p-menthen8-ol ("a-terpineol"), 3-hydroxy-2-bornanone (3-hydroxy-camphor). Stereoiso mers can be distinguished b y systematic prefixes. Other Terpene Classes The few tricyclic terpenes are named by an extension of the Baeyer bicyclo nomenclature; thus, the so-called cyclofenchene is l,3,3-trimethyltricyclo[2.2.1.O^Jheptane. Proposals for naming ses quiterpenes and polyterpenes are with held pending agreement on the simpler terpenes. Terpene Radical Names The names of radicals derived from terpenes and their derivatives are formed in the usual way with the endings such as -yl, -ylidene, the point of attachment of the radical taking the lowest position number that is consistent with the fixed numbering of the terpene molecule. The name pinanyl for the univalent radical of pinane is an exception to the usual rule; it should b e "pinyl" but the latter name has another, older meaning. Otherwise the formation of terpene radical names is regular. It can b e seen from the above that the system which the subcommittee is shaping is no radical departure but follows many of the customary terpene practices. It does, however, eliminate many incon sistencies and many trivial names that no longer serve any useful purpose. • 221 North King St., Xenia, Ohio.
VOLUME
3 0,
NO.
9
approximately 20x
Filament Spun Y a r n
Here's a list of our synthetic filter cloths and the kind of yarn from' which they are> manufactured:
Cloth Nylon Orion * Dynel Vinyon-Nf Vincel*· Glass
Filament Yes Yes No Yes Yes No
Spun Yes Yes Yes No No Yes
Note: Fabrics o f blended filament a n d spun yarns are a l s o a v a i l a b l e in several of these fibers.
F
ilament yarn fabrics by their very nature are smooth surfaced, affording exceptional tensile strength, high capacity and clean discharge. At times, however, they may not give desired clority o f filtrate or the resilience necessary for proper sealing. In such instances, a s p u n yarn fabric can excel because its fibrousftsurface aids in t h e entrapment o f fine particles. In addition, a spun yarn creates a bulkier compressible cloth. Blended fabrics are designed to offer a maximum of strength with a hicjher degree o f retention as well. Experi ence will tell you which is the controlling f a c t o r when ordering cloth; or, if you would like, we'll be glad to supply comparative samples. Consider the value to you of our two-way service in connection with filter cloths: a wide variety of synthetic yarn cloths, In addition to our cotton cloth, which have many desirable characteristics -for h a n dling chemicals, hot and cold; and a selection Remember, we have at our o f yarn or combination of yarns to best fit y o u r New Haven and Salt Lake City filtering requirements. factories, facilities for making up elements for any type of •TM — E . I. DuPont de Nemours & Co. Inc. *TM —UCC filter in all the available fibers. • • T M —NFMC (applied for) We A vet* of c^nL^tùA
« = / « / / « /J7e&iA
fat
ο vet
e S^atioHcil jPilter Media (QoTJÙ General Offices & Mills: New Haven 14, Conn. Western Office & Factory: Salt Lake City 1, Utah Sales Chicago, I I I .
Cincinnati, Ohio
2627 West 19th St.
Rotelawn Center Bldg.
MAR OH
3,
1952
Offices— Représentatives Houston, Ttxos
1406 Second National Bank Bldg.
Oslo, Norway
Johannesburg, South Africa
Nicolai Friis
Edward L. Boteman
931
