RESUMO
[figure: see text] Cavitand bowls carrying two derivatizable groups at the rim have been efficiently prepared through a selective lithium/halogen exchange-electrophile quenching procedure. This methodology lends itself to the single-step preparation of the first all carbon-linked bis-bowl and a new class of inherently chiral cavitands.
RESUMO
Despite the existence of several protocols, problems appear to persist in the small scale chemical synthesis of radiolabeled 11-ketotestosterone from cortisol. We investigated the possibilities of using the mild oxidant pyridinium dichromate for the oxidative cleavage of the dihydroxyacetone side chain of cortisol and 17 beta-hydroxysteroid dehydrogenase for the subsequent reduction of the resulting 17-keto group. Our protocol has resulted in consistently high yields of both the intermediate, adrenosterone (70-80%), and the product, 11-ketotestosterone (up to 60%). This, taken together with the convenience and relatively low cost of our method, recommends the protocol for its use for the synthesis of [3H]-11-ketotestosterone for endocrine studies.
Assuntos
Hidrocortisona/química , Testosterona/análogos & derivados , Androstenos/química , Androstenos/metabolismo , Hidroxiesteroide Desidrogenases/metabolismo , Oxirredução , Compostos de Piridínio , Testosterona/síntese química , Testosterona/metabolismo , TrítioRESUMO
Our experience with congenital pelvic arteriovenous malformations is described. Presenting symptoms may be chronic and not always confined to the pelvis. Experience with arteriovenous malformations is limited. Preoperative angiography is essential to delineate the vascular supply to the lesion. Surgery has been successful in cases where complete tumor removal is performed. Careful long term follow-up is required for early detection of recurrence and follow-up angiography is recommended.
