€544. A Convenient Solid for Calibration of the Gouy MagneticSusceptibility Apparatus. By B. N. FIGGIS and R. S. NYHOLM. THE measurement of magnetic susceptibilities by the Gouy method is a relative one, the apparatus being calibrated in terms of a substance of known susceptibility, for which water, nickel chloride solution, and powdered cupric sulphate pentahydrate or ferrous ammonium sulphate hexahydrate have been used. The low suceptibility of water is often inconvenient if small tubes are being calibrated. Nickel chloride solution requires accurate analysis before use and ferrous ammonium sulphate is often of questionable purity. This substance and copper sulphate do not pack well and several different values for the susceptibilities of both solids have been reported.The required properties for a calibrant are: (1) Readily available pure;(2) an accurately known and moderate susceptibility (xg = ;(3) stability in moist air;(4) xg must vary in a known and simple way, at least at room temperature; (5) easily and reproducibly packable into the Gouy tube. The complex mercury tetrathiocyanatocobaltate HgCo(CNS), offers some advantages and its susceptibility has therefore been accurately determined. at 20' 1 being used as reference, the gram susceptibility of the complex is 16.44 (-&O.OS) x at 20".As reported elsewhere,l it obeys the Curie-Weiss law, xg cc (T + lO)-l where T is expressed

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Miltirone (I), a diterpenoid quinone has been synthesised from p-bromoanisole, the key intermediate being 6-isopropyl-7-methoxy-I -tetralone (VI). A Reformatsky reaction on compound (VI) with methyl y-bromocrotonate, followed by aromatisation, treatment with methylmagnesium iodide, and cyclisation gave 1.2.3.4-tetrahydro-1 ,I -dimethyl-6-methoxy-7-isopropylphenanthrene. The corresponding phenol was oxidised to a quinone, identical with miltirone, either by air or by Fremy's salt.

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Summavy 2-Aryl-6-oxocyclohex-1-enylacetic esters are found to undergo dehydrogenation to phenols with concomitant loss of acetate side chain on exposure to sodium hydride and dimethylformamide at 100".SODIUM hydride in dimethylformamide (DMF) has been widely used for generation of carbanions from active methylene compounds prior to their a1kylation.l The system possesses certain advantages over other metalsolvent combinations2 and no abnormal side-reaction has yet been reported. We wanted to use the method for the introduction of angular methyl at C(l) in some cyclohexenone derivatives [e.g., (I; Ar = fl-naphthyl)],3~* to obtain products easily convertible into hydroaromatic steroids.5 The feasibility of such reaction depends on the initial formation of a carbanionic centre a t C(3) and is already well precede~ited.~ However, treatment of the ester or the 0 ! !

Methyl 2-aryl-6-oxocyclohex-1 -enylacetates ( I ; R = Me) and some related compounds, when heated with a number of base-solvent systems, undergo aromatisation, the cyclohexenone system becoming phenolic with concomitant loss of the acetate side-chain. Sodium hydride in dimethylformamide at 100' is most effective for this transformation, and few alkoxides in aprotic solvents also catalyse the reaction. The mechanism is discussed.The results of dehydrogenation using pyridine hydrochloride are also reported.

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