Substituted alkyl 2H-pyran-5-carboxylates, 1, have been condensed with methyl 2-(triphenylarsoranylidene) ethanoate, 14a, to form substituted 3-vinyl-1,2-cyclopropanedicarboxylates, 15, and, in a number of cases, 2,3dihydro-3-vinyl-2,4-furandicarboxylates, 16. NMR experiments showed that for the majority of cyclopropane products formed, the cyclopropane ring hydrogen atoms have the trans conÐguration. This was validated by molecular orbital calculations. Biological screening tests revealed that these compounds showed some ectoparasiticidal activity. * E-mail : cornelis.moorho †=molsci.csiro.au ¤ Non-SI unit employed : 1 kcal B 4.18 kJ.
Sum-ary The preparation of the two most active tetrehydrocannabinol analogs mentioned by Adams1) is well under way. For one compound ten of the fourteen necessary steps have been completed, and for the other, seven. Concurrently with the above work, various synthetic methods have been tried for the preparation of intermediates which could lead to nitrogen and sulfur analogs of tetrahydrocannabinol. '~~~7 '4. "•• U•~D • ÷ " "%' ,N
NOTES 1835 excluded. The main fraction (379 g. + 26 g. from forerun = 405 g. or 73 mole-% conversion) was I, b.p. 215°/750 mm., n2Ds 1.4550 (hydrol. chlorine, 42.3%; caled., 42.2%). ß-Cyanoethylethyldichlorosilane (III). Similar treatment of 254 g. (1.35 moles) of II with ethylmagnesium chloride prepared from 36.4 g (1.5 moles) of magnesium turnings and 97 g. (1.5 moles) of rthyl chloride in a total of 1 1. of tetrahydrofuran at -50°g ave after filtration and removal of the solvent, 205 g. of crude product. Fractional distillation gave 168 g. total (conversion, 69 mole-%) of III as the main product (hydrol. chlorine, 37.9%; caled., 38.9%) b.p. 234-235°/751 mm. and a forerun b.p. 200-234°/751 mm. (hydrol. chlorine, 34.8%) consisting of a mixture of 21.5 g. (conversion, 9 mole-%) of /3-cyanoethylchlorodiethylsilane (caled, hydrol. chlorine, 20.2%) and 5 g. of III.
Silicones DivisionUnion Carbide Corporation ToNAWANDA, N. Y.
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