The circular dichroism (cd) spectra of nineteen aporphines of widely differing substitution patterns have been examined between 200 and 400 nm. Three major cd band systems exist, in the 220, 270-280, and 300 nm region. Two intense oppositely-signed Cotton effects (CE's) between 200 and 250 nm are substitutionindependent and configuration-dependent, as is the third CE at 270-283 nm. In the region 293-327 nm, there are two further CE's which are substitution-dependent. In the case of symmetrically (1,2,10,11) substituted aporphines, the bands in the 300 nm region are split into two oppositely-signed CE's with a pattern similar to that observed for the 220 nm region. 'Publication No. 30 in the series Optical Rotatory Dispersion and Absolute Configuration, 80 Cd spectra were measured in 95% ethanol on a Roussel-Jouan Mark II dichrograph or a Jasco ORD-CD5 spectropolarimeter at 20°.

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Uv spectra were recorded in 957, ethanol with a Cary 14 instrument.

The McFadyen-Stevens reaction of 1-benzenesulfonyl-2-benzoylhydrazines to give benzaldehydes has been shown to proceed with first-order kinetics with respect to the anion of the hydrazine. A Hammett plot gave p = -1.38 and a deuterium isotope effect of k~/ k~ = 2.28 a t 160" (equivalent to ea. 4.5 at 25") was obtained. The method provides a convenient and rapid synthesis of 1-deuteriobenzaldehydes. A mechanism is proposed involving a fast reversible a-elimination of sulfinate ion to give an intermediate benzoylaminonitrene, followed by tautomerism of the latter with loss of nitrogen to rearrange to the aldehyde.The McFadyen-Stevens reaction describes the base-catalyzed thermal decomposition of acylbenzenesulfonhydrazides 1 in ethylene glycol at 160" to give an aldehyde, with loss of nitrogen and sulfinate ion. The intermediary formation of an acyldiimide was suggested by McFadyen and Stevens,l and successive bimolecular elimination mechanisms have been put forward for both the first2 (eq 1) and the second3 (eq 2) steps of the reaction.A somewhat related method of preparing aldehydes4,5 involves the base-catalyzed oxidation of monoacylhydrazides, using potassium ferricyanide4 or sodium metaperiodate5 (eq 3). B -3 H ArCO-N-YH-SO,Ar 1 3 cc -+ ArCO-N=NH + ArS0,-(1) BqH-Q=-N-QOAr -N, + BH + -COAT -+ HCOAr (2) ArCOSHNH, -+ ArCON=KH --+ ArCHO + N L (3)In both reactions the yield of aldehyde is enhanced1,4 by the presence of ortho,para-directing groups in the 2 or 4 position of the aroylhydrazide moiety, while meta-directing groups in these positions depress the formation of aldehydes1,6 and lead instead to the symmetrical diacylhydrazides.637 The similarity between these reactions suggested6 that both occur by a common mechanism. It was therefore proposed8 that electron-withdrawing substituents Y in the 4 position of the benzenesulfonyl group in 1 might facilitate the elimination step and thereby increase the yield of aldehyde. However, the yield of 4-methylthiazole-5-aldehyde actually decreased with the variation in the 4 substituent in the order CH30 > H > Br > NO2 when a 1-(4-substituted benzenesulfony1)-2-(4-methvlthiazole-5-carbony1)hydrazine was subjected to the McFadyen-Stevens reaction.8It was postulated,s in agreement with a previous prop o~a l ,~ that the initial reaction is the rapid extraction of a proton from the sulfonamide nitroger, to give the anion 2 1 X e C O N H % ! , 0 2 * 2 and that this anion undergoes a 1,2-hydride shift (eq 4) which would be promoted when Y is electron donating.The resulting sulfonylazoalkoxide ion could finally decomposes (eq 5 ) to the aldehyde, nitrogen, and arylsulfi- 70