A NEW SYNTHETIC METHOD FOR γ-SUBSTITUTED Δα,β-BUTENOLIDES
نویسندگان
چکیده
منابع مشابه
16-Substituted steroids. XV. A new synthetic method for 16-ketosteroids.
In 1941 (1) the senior author entered the field of 16-substituted steroids with the view of preparing all of the three possible 16,17-epimers of natural estriol. Since that time two of these three epimers, 16-epiestriol (isoestriol-A) (2) and 17-epiestriol (3), have become available through our efforts and those of the Swiss investigators. In 1952 the present authors made an attempt to prepare ...
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هدف اصلی از این تحقیق به دست آوردن و مقایسه حق بیمه باورمندی در مدل های شمارشی گزارش نشده برای داده های طولی می باشد. در این تحقیق حق بیمه های پبش گویی بر اساس توابع ضرر مربع خطا و نمایی محاسبه شده و با هم مقایسه می شود. تمایل به گرفتن پاداش و جایزه یکی از دلایل مهم برای گزارش ندادن تصادفات می باشد و افراد برای استفاده از تخفیف اغلب از گزارش تصادفات با هزینه پائین خودداری می کنند، در این تحقیق ...
15 صفحه اولDiastereo- and enantioselective direct vinylogous Michael addition of γ-substituted butenolides to 2-enoylpyridines catalyzed by chiral bifunctional amine-squaramides.
The diastereo- and enantioselective direct vinylogous Michael addition reaction of γ-substituted butenolides to 2-enoylpyridines has been achieved. A range of γ,γ-disubstituted butenolide derivatives, bearing two consecutive tri- and tetrasubstituted stereogenic centers, were readily obtained in good yields with excellent stereoselectivities (up to >99 : 1 dr and >99% ee).
متن کاملA Novel Method for Synthesis of Substituted Naphthofurans and Naphthopyrans
Substituted naphthofurans and naphthopyrans were constructed at high temperature from allyl or propargyl naphthyl ethers via Claisen rearrangement in moderate to good yields. Also, substituted (trimethylsilyl)-naphthofurans were synthesized from the corresponding naphtofurans.
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ژورنال
عنوان ژورنال: Chemistry Letters
سال: 1974
ISSN: 0366-7022,1348-0715
DOI: 10.1246/cl.1974.385