BN1 9QJ3@-Acetoxylanost-8-ene has been photo-oxygenated in the presence of a dye and p-nitrobenzenesulphonyl chloride to yield, among other products, the Criegee rearrangement product 3~-acetoxy-8,9-epoxy-8,9-secolanosta-7,9(1l)-diene (XV; R = Ac) and 3~-acetoxy-7a-hydroperoxylanost-8-ene ( V I I ; R = Ac). These are thought to arise from 3(3-acetoxy-9a-hydroperoxylanost-7-ene (I1 ; R = Ac) ; their transformations are reported. The bridged cyclodeca-I ,6-diene system in (XV) takes part in transannular reactions. t Presed address : Sterling Chemical Laboratory, Yale Univer-For leading references see R. B. Clayton, Quart. Rev., 1965,photo-oxygenation in the presence of P-nitrobenzenesulphonyl chloride so that if any 9ct-hydroperoxide were formed it might be esterified and the resultant peroxyester solvolysed in situ to yield the 9,14-epoxide (111; R = Ac).
Reactions of the triplet carbene, diphenylmethylene, with the non-conjugated annular dienes, norbornadiene and cyclo-octa-l,5-diene, have been studied in the hope of achieving transannular addition which might give useful synthetic entry into bridged systems. New compounds were obtained but there was no evidence for the presence of any transannular adducts.SKELL 1-3 has suggested that, whereas singlet carbene may add concertedly to an olefin to yield a cyclopropane, triplet carbene cannot add concertedly to an olefin with spin conservation. The singlet reaction would result in retention of the stereochemistry of the original olefin in the product cyclopropane whereas the triplet reaction would result in loss of this stereospecificity.
Die bei der Photolyse des Diazomethans (I) in Gegenwart von Norbornadien (II) in Äther entstehende Titelverbindung lagert sich an eine Doppelbindung von (II) zu dem Tricycloocten (III) an.
Durch Umsetzung von Adenin (I) mit Benzoylchlorid (II) oder den Carbonsäureanhydriden (IV) in Pyridin werden die ö‐Acylaminopurine (III) und (V) dargestellt.
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