mg of the product by vpc gave 7.4 mg of partially crystalline material having mp 93.5-95.5°(softens at 91°). Sublimation gave ( + )-occidentalol (2) having mp 94.2-95.0°; uv max 263.5 nm (« 4300, 3940); [«]"d +364°, +360°(c 0.36, CHCl«j. The nmr (microcavity tube) and ir spectra of synthetic ( + )-occidentalol were essentially identical with spectra determined on a sample of authentic (+ )-occidentalol (kindly supplied by Dr. E. von Rudloff) which exhibited mp 94-95.5°; [ ] 6 +341°(c0.53); uv max 263.5 nm (e 4450).C.-Treatment of the mixture (230 mg) containing ( + )-12 (co. 86 mg) from photolysis run C with CH8Li in Et20 followed by preparative vpc afforded 35 mg of ( + )-occidentalol (2), [a] 27d + 290°( c 2.92); vpc showed >85% purity. Further purification of 29.2 mg of (+ )-2 by vpc gave 14.7 mg of a partly crystalline glass, [a]®d +352°(c 0.19, CFIC13). Sublimation of the glassy material gave ( + )-occidentalol (2) as needles, mp 91.0-92.5°, uv max 264 nm (e 3905).( + )-ll-Hydroxy-55,7afí'-eudesma-l,3-diene-A solution of ( -)-ll (40 mg from run A in 2 ml of Et20 at 0°) was treated with methyllithium (1 ml of 2.3 M solution in Et20) under N2. A normal work-up gave an oil which was purified by glpc column 190°, head 216°)42 to yield 28 mg (70%) of ( + )-l as a viscous liquid: [a] 25d +60.7°( c 0.15); uv max 266 nm (e 4900) and 273 (shoulder); ORD (c 0.0029) |>]2S6 +13,300°, [0]263 0°, [0]234 -28,300°; CD (c 0.0029) [0]jei +27,600°, [6]m +24,500°(shoulder), and inflec-
Die Photolyse der aus Acylchloriden und Tris‐[trimethylsilyl]‐silyl‐Li synthetisierten Acylsilane (I) ergibt die Silaethylene (II), wie durch ihre Kopf‐an‐Kopf‐Dimerisierung zu den lß‐Disilacyclobutanen (III) oder die Einfangreaktionen mit Methanol, Wasser oder 2,3‐Butadien unter Bildung der Produkte (IV) bzw. (V) bestätigt wird.
Die Cyclobutenderivate (I), (III) bzw. (V) (dargestellt durch Kondensation der Salze der entsprechenden cis‐1,2‐Dimercapto‐äthene mit cis‐3 ,4‐Dichlor‐cyclobuten) verlieren durch Thermolyse oder Photolyse Schwefel und gehen dabei in die Aromaten (II), (IV) bzw. (VI) (27‐6 1% Ausbeute) über.
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