The boat form of cyclohexane as viewed by Midwestern sailors

at the bow and stern of the boat the bowsprit and flagpole hydrogens, respectively.1 Since it is not immediately evi- dent which way the cyclohexane b...
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letters Laboratory Safety with Sodium Bis(2-methoxy-ethoxy) Aluminum Hydride To the Editor: Sodium bis(2-methoxy-ethoxy) aluminum bydride is assuredlv to be welcomed on account of its contribution to laboratory safely in reducing fire and explosion risks IKushner. A. S.. and Varcariello,. T.,. J. CHEM. KI)UC., 50,154 (1973)l. It does, however, appear unfortunate that the new material is supplied, and its use recommended, in benzene solution. The vapor of benzene is now becoming recognized as highly toxic, since inhalation can cause severe damage to brain tissue and bone marrow (see, e.g., recent correspondence in Chemistry in Britain, especially on page 133 of its March issue). Accordingly it is necessary to add to the safety precautions, listed in footnote 4, the necessity of a fume-cupboard when handling the reagent.

L. S. Bull Sorrh East London I'olvrechn~r London El5 l1.Z.England

The daneer of such " eraohic. . . classical nomenclature is demonstrated by this case, however, for all chemists are not eood sailors. Thus the land-locked. midwestern authors; H. Hart and R: Scbuetz ["organic Chemistry: A Short Course," (4th ed.), Houghton-Mifflin, Boston, Mass., 1972, pp. 39-40], describe an upright bowsprit and thus presumedly a flagpole a t half-mast. The former midwesterner Eliel ["Stereochemistry of Carbon Compounds," McGraw-Hill, New York, 1962, pp. 205 and 2071 also favors a vertical bowsnrit but does flv the flae oroudly in a vertical fashion. +his leads to a"consider&iion of the unfavorable van der Waals interaction denoted bv this author to be the "bowsprit-flagpole" interaction i ~ l i e l , Allinger, Angyal and Morrison, "Conformational Analysis," Interscience Publishers (Division of Wiley & Sons), New York, 1956, p. 371, which would be better classified as the "bow and stern flagpole" interaction mentioned by Klyne [Progress in Stereochem., 1, 40 (1954)l. To ensure an equal opportunity in conformational analysis for the sailors and non-sailors, the correct designations for the hydrogens in the boat forms are given below.

The Boat Form of Cyclohexane a s Viewed by Midwestern

Sailors To the Editor: The organic chemist has always felt most comfortable with a physical picture to relate to abstract ideas. This has often resulted in colorful nomenclature to describe these physical pictures. While the names for the kinds of hydrogens found on the chair form of cyclohexane were based on relationships to geometry, the whimsical vision of the "boat" form provided an outlet for chemical, classical sailors to indulge their fancy. Thus in obvious analogy to the sailing ships of yore, Angyal and Mills [Reu. f i r e Appl. Chem., Aust., 2, 185 (1952)l named the hydrogens a t the how and stern of the boat the bowsprit and flagpole hydrogens, respectively.' Since it is not immediately evident which way the cyclohexane boat is going, the other hydrogens could equally he called the flagpole or bowsprit hydrogen.

In the diagram f p = flagpole; bs = bowsprit; Be = boatequatorial; and Ba = boat-axial. Although A. S. Smith (Chem. and Ind., 353 (1955)) credits Drs. Angyal and Mills for their introduction of these terms, Dr. Angyal in a private communication claims the use of "flagpole" only and suggests that Dr. Klyne introduced the term "bowsprit." Gloria G. Lyle and Robert E. Lyle University of New Hampshire Durham, New Hampshire 03824

Volume 50, Number 9. September 1973 / 655