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4-Phenyl-4,6,7,8,9,10-hexahydrothieno[2,3-g][1,4]oxazonine-8-carbonitrile (5a) and the analogous 4-phenyl-6,7,8,9,10,11-hexahydro-4H-thieno[2,3-h][1,5]oxazecine-9-carbonitrile (5b) were preparedin moderate yields by cyanogen bromide-induced ring expansion of the appropriate ω-(tetrahydrothieno[3,2-c]pyridyl)alkan-1-ol precursors (3). N-Methyl derivatives of these new fused medium-ring heterocyclic systems were prepared by standard methods.

10-Phenyl-4,5,6,7,8,10-hexahydrothieno[3,2-g][1,4]oxazonine-6-carbonitrile (6a) and 11-phenyl-4,6,7,8,9,11-hexahydro-5H-thieno[3,2-h][1,5]oxazecine-6-carbonitrile (7a) were prepared in moderate yields by cyanogen bromide-induced ring expansion of tetrahydrothieno [2,3- c] pyridinylalkanol precursors (4a) and (5a), respectively. 1-Phenyl-1,3,4,5,6,7-hexahydro[1]- benzothieno [3,2-g][1,4]oxazonine-5-carbonitrile (6b) and 1-phenyl-3,4,5,6,7,8-hexahydro-1H- [1] benzothieno [3,2-h][1,5]oxazecine-6-carbonitrie (7b) were similarly prepared from the [1] benzothieno [2,3-c] pyridinylalkanol precursors (4b) and (5b). The medium-ring cyanamides (6b) and (7b) were converted by standard methods into their N-methyl analogues (8b) and (9b). 6-Methyl-8-phenyl-4,5,6,8-tetrahydrothieno[3,2-e][1,2] oxazepine (13) was prepared by thermal Meisenheimer rearrangement of the corresponding tertiary amine N-oxide (12). The compounds (6a, b), (7a, b) and (13) are each the first reported examples of new heterocyclic systems. The crystal and molecular structure of (6b) has been determined by X-ray crystallographic methods.

Reaction of the reduced pyrrolo [2,1-a] isoquinoline amine (1a) with cyanogen bromide in the presence of methanol gave the medium-ring cyanamide derivative 7,9,10-trimethoxy-2,3,4,5,6,7-hexahydro-1H-3- benzazonine-3-carbonitrile (2a). Analogous products were also obtained from reaction of the reduced 5H-oxazolo[2,3-a] isoquinoline , 2H- benzo [a] quinolizine , 2H,6H-[1,3] oxazino [2,3-a] isoquinoline and [1,4] oxazino [3,4-a] isoquinoline derivatives (1b-e), whereas the reduced 3H-oxazolo[4,3-a] isoquinoline and 5H-oxazolo[2,3-a] isoquinoline derivatives (1f) and (8) gave 1-(2,4-dioxapentyl)-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline-2-carbonitrile (5a) and N-[2-(2-benzoyl-4,5-dimethoxyphenyl)ethyl]-N- methylcyanamide (9) respectively, the latter in low yield. The medium-sized heterocyclic derivatives (2f-h) were also obtained from cyanogen -bromide-mediated water solvolysis reactions of (1a), (1c) and (1e). The cyanamides (2a-h), (5a) and (9) have been converted into the respective tertiary amine derivatives (3a- h), (5c) and (11), with concomitant reduction of the carbonyl group in the last case. The crystal and molecular structure of 1,10,11- trimethoxy-3,4,5,6,7,8-hexahydro-1H-2,6-benzoxazecine-6-carbonitrile (2d) and 1-hydroxy-10,11-dimethoxy-1,4,5,6,7,8-hexahydro-2H-3,6- benzoxazecine-6-carbonitrile (2h) have been determined by single- crystal X-ray methods.

The preparation of the tetracyclic derivatives, (5) and (11), thienanalogues of the tetrahydroprotoberberine alkaloids, is described. Cyanogen bromide-induced water solvolysis of these isomeric compounds proceeded by different routes. 9,10-Dimethoxy-4,7,12,12a- tetrahydro-5H-benzo[g] thieno [3,2-a] quinolizine (11) under these conditions gave as the major product 4-(2-hydroxymethyl-4,5- dimethoxybenzyl )-4,5,6,7-tetrahydrothieno[3,2-c]pyridine-5- carbonitrile (12); no azecino derivatives were detected. By contrast such cleavage of 2,3-dimethoxy-5,8,12,12a-tetrahydro-6H- benzo [a] thieno [3,2-g] quinolizine (5) gave a major solvolytic ring- expanded product, 12-hydroxy-9,10-dimethoxy-4,5,6,7,12,13- hexahydrothieno [3,2-e][3]benzazecine-5-carbonitrile (15), and a minor elimination product, (E)-9,10-dimethoxy-4,5,6,7-tetrahydrothieno[3,2- e][3]benzazecine-5-carbonitrile (16). These last two compounds are examples of a new tricyclic ring system. From functional group interconversions of (15) was derived the N- methyl ketone (18), the first thieno analogue of the protopine alkaloid system. The crystal and molecular structure of this compound, 9,10-dimethoxy-5-methyl-4,5,6,7,12,13-hexahydrothieno[3,2-e][3] benzazecin - 12-one (18), has been determined by single-crystal X-ray methods.

The heterocyclic derivatives, 8,9-dimethoxy-3-methyl-1-phenyl-3,4,5,6- tetrahydro-1H-2,3-benzoxazocine(3a) and 9,10-dimethoxy-3-methyl-1- phenyl-1,3,4,5,6,7-hexahydro-2,3-benzoxazonine (3b),examples of two new ring systems, have been prepared by Meisenheimer rearrangement of the corresponding 2-benzazepine and 2-benzazocine N-oxide derivatives (2a) and (2b). The Bischler-Napieralski-type cyclization reaction was used in the preparation of the tertiary amine precursors of these N-oxides reaction conditions for the cyclization were critical and phosphorus oxychloride in refluxing butanenitrile was found to give the best yields of the seven- or eight-membered cyclic imine intermediates. Reductive cleavage of the benzoxazocine derivative (3a) with zinc in acetic acid followed by N-methylation gave the expected product, [2-{3- (dimethylamino)propyl}-4,5-di-methoxyphenyl]phenylmethanol (12). The crystal and molecular structure of (3a) has been determined by X-ray crystallographic analysis.

The major alkaloids of Anthocercis tasmanica are shown to be hyoscine and nicotine. Anthocercis tasmanica is endemic in Tasmania and is one of some twenty species of Anthocercis, all indigenous to Austra1ia.l Three Western Australian species have been found2s3 to contain a variety of tropane alkaloids, most of which also occur in other solanaceous plants. A. tasmanica is now quite rare, and only a few bushes near the east coast of Tasmania are known to exist. Extraction of a sample of air-dried leaves and stems gave 0.064% of crude base, which from t.1.c. contained two main alkaloids and several minor ones. The major alkaloid, separated by preparative t.l.c., gave an n.m.r. spectrum corresponding closely to that of hyoscine; a second oily base was considerably more volatile, and had a pronounced pyridine-like smell. On t.1.c. it had an R, corresponding to that of nicotine, and the spot gave the same characteristic colour as nicotine when sprayed with iodoplatinate reagent.4 A sample isolated by preparative t.1.c. gave an n.m.r. spectrum which agreed with that of nicotine. The crude alkaloids extracted from a further quantity of plant material were separated into steam-volatile and involatile fractions. The first fraction formed a picrate identical with (-)-nicotine picrate, and the second a hydrobromide identical with that of (-)-hyoscine. T.1.c. showed the presence of other alkaloids, but in quantities insufficient for further examination; some of them are evidently steam-volatile from g.1.c.-m.s. of the crude nicotine fraction, but no indication of the presence of nornicotine could be observed. Hyoscine has been found amongst the alkaloids of A. lit tore^,^ and has been identified by t.1.c. as occurring in A. v i~cosa .~ These species contain other tropane alkaloids, but no nicotine-type bases have been recorded in them; A. tasmanica is one Curtis, W. M., 'The Student's Flora of Tasmania' Part 3, p. 509 (Government Printer, Tasmania: Hobart 1967). Cannon, J. R., Joshi, K. R., Meehan, G . V., and Williams, J. R., Aust. J. Chem., 1969, 22, 221. Evans, W. C., and Treagust, P. G., Phytochemistry, 1973,12,2505. Smith, I., 'Chromatographic and Electrophoretic Techniques' 2nd Edn, Vol. I, p. 98 (Heinemann Medical Books: London 1960). Short Communications of the few solanaceous plants in which both these alkaloid types have been found to occur t~ge the r .~

Melt pyrolysis of the cis-6,7-dimethoxy-2-methyl-1-phenyl-1,2,3,4- tetrahydroisoquinoline N-oxide (2b) afforded the Meisenheimer rearrangement product, 7,8-dimethoxy-3-methyl-1-phenyl-1,3,4,5- tetrahydro-2,3-benzoxazepine (5b), in good yield, as did pyrolysis of the corresponding trans-N-oxide (3b) (in a melt) or a mixture of (2b) and (3b) (melt or in solution). The synthesis of the 1-deuterated analogue, (5c), of (5b) is described, together with products derived from (5b) by cleavage of the N-O bond which were used to confirm its structure. Meisenheimer rearrangement of the N-oxides (10) and (11) of 6,7-dimethoxy-1-(3,4-dimethoxyphenyl)-2-methyl-1,2,3,4-tetrahydroisoquinoline and 2-methyl-1-phenyl-1,2,3,4- tetrahydroisoquinoline gave the analogous 2,3-benzoxazepine derivatives (12) and (13), respectively.