Novel Approach to the Zaragozic Acids. Enantioselective Total Synthesis of 6,7-Dideoxysqualestatin H5
作者:Satoru Naito、Maya Escobar、Philip R. Kym、Spiros Liras、Stephen F. Martin
DOI:10.1021/jo011157s
日期:2002.6.1
The totalsynthesis of 6,7-dideoxysqualestatin H5 (3) has been completed by a concise approach that features the stereoselective intramolecular vinylogous aldol reaction of the furoic ester 25a to give 30 or its trimethylsilyl ether derivative 34, which possess the requisite absolute stereochemistry at C(3)-C(5) of 3. Compound 34 was reduced to the saturated bislactone 39, and the C(1) side chain subunit
Durch [4+2] Cycloaddition mit „inversem”︁ Elektronenbedarf des Triazins 1 und Dienophilen mit semicyclischer Doppelbindung wie 2a‐d erhält man in regioselektiver Reaktion Spiroverbindungen des Typs 3. Deren Hydrolyse führt zu den Spiro‐tetrahydropyridinonen 5a‐d mit strukturellen Ähnlichkeiten zum Pyrithyldion (Persedon®).
Reaction of dimethyl acetylenedicarboxylate with derivatives of malonic acid: pentamethoxycarbonylcyclopentadienide anion, tetramethoxy-carbonylcyclopentadienone, cyanotetramethoxyfulvenolate anion, and related compounds
作者:R. C. Cookson、J. B. Henstock、J. Hudec、B. R. D. Whitear
DOI:10.1039/j39670001986
日期:——
formulation of the adducts of dimethyl malonate with dimethylacetylenedicarboxylate in the presence of pyridine and acetic acid as tautomeric octamethyl cycloheptadienoctacarboxylates [(III) and (IV)] is confirmed. Both tautomers, or the analogues from other esters of malonicacid, are converted by potassium acetate into Diels' potassium pentamethoxycarbonylcyclopentadienide (VIa). Diazomethane methylates
A novel method of synthesis of 1,2-diketones from 1,2-diols using N-bromosuccinimide
作者:Jitender M Khurana、Bhaskar M Kandpal
DOI:10.1016/s0040-4039(03)01075-x
日期:2003.6
A simple and convenient procedure is reported for the synthesis of benzils and aliphatic 1,2-diketones of cyclic and open chain compounds from corresponding hydrobenzoins and 1,2-diols by refluxing with N-bromosuccinimide in carbon tetrachloride in presence or absence of pyridine.
(2-imidazolin-2-yl) fused heteropyridine compounds, intermediates for
申请人:American Cyanamid Company
公开号:US05252538A1
公开(公告)日:1993-10-12
There are provided novel (2-imidazolin-2-yl) fused heteropyridine compounds, and intermediate compounds for the preparation thereof, and a method for controlling a wide variety of annual and perennial plant species therewith.