evaporated in vacuo. The residue was purified by radial chromatography, eluting with 10% MeOH/CH2Cl2 to yield 46 mg (44%) of product: [a]p -125°(c 0.2, CHC13) (lit. -128).23Reduction of Egenine and Corytensine. To a solution of the phthalide isoquinoline hemiacetal in ethanol was added 1 molar equiv of NaBH4. The reaction mixture was stirred overnight at room temperature. After removal of the solvent in vacuo, saturated ammonium chloride was added, and the mixture was extracted with three portions of CH2C12. The combined organic phases were dried over MgS04 and evaporated in vacuo. The residue was purified by radial chromatography, eluting with 10% MeOH/CH2Cl2. Bicucullinediol (17e) was obtained in 73% yield (8 mg) from 11 mg of 2: [o]D +16.3°( c, 0.4, CHC13) (lit. -17°for the [S-(R*,S*)] isomer).18Adlumidinediol (17t) was obtained in 74% yield (14 mg) from 19 mg of 4: [a]D +25°(c 0.3, CHC13) (lit. -24°for the [S-(R*fl*)] isomer).18Acknowledgment. This work was generously supported by the National Institutes of Health: grant GM-37985 supported this work and grants RR-03351 and RR-04680 funded NMR and MS facilities, respectively. K.S.R. also thanks the University of Miami for a Maytag Fellowship.Supplementary Material Available: NMR spectra for compounds 2, 4-6, and 12-16 (18 pages). Ordering information is given on any current masthead page.
Synthesis of β‐Nitroalkenyl‐benzylphosphorylderivatives
Starting from methoxy‐chlormethylbenzaldehydes 2 the benzylphosphonates and ‐phosphinoxides 3 A, B had been synthesized, which could be transformed via the Schiff‐bases 4 A, B to phosphorylated nitrostyrenes 5 A, B and nitropropenylbenzenederivatives 6 A, B. The phosphonoacids 3 Ad, 3 Bd and 6 Ba could be prepared from the corresponding esters by direct acidic hydrolysis or by dealkylation with trimethylsilylbromide and hydrolysis of the trimethylsilylesters respectively.
Reaction of chloroglyoxime 1 with aryl isocyanates yielded monocarbamates 3, and chlorooxime functional group was unchanged. The 1,3‐cycloaddition of nitrile N‐oxides generated from 3 to methyl methacrylate gave isoxazole derivatives 5. Compounds 5 were also obtained by carbamoylation of 3‐formyl‐4‐hydro‐5‐methyl‐5‐methoxycarbonylisoxazole oxime 6.
The selectivity of chloroglyoxime carbamoylation and the poor reactivity of chlorooxime group is general. Examples, involving another oximes and their halogeno derivatives are given.
α‐Substituted Phosphonates. 39. Methane‐diphosphonic Esters by U.V.‐Induced Michaelis‐Becker‐Reaction
Dibromomethane resp. chlorbromomethane reacts with sodium dialkyl phosphite in heptane‐/liq.NH3 or in liq. NH3 by u.v. irradiation at low temperatures to give in good yields methane diphosphonic acid tetraalkylesters 1. In the same manner with sodium diethyl thionophosphite the corresponding methane‐bis‐thiophosphonic acid tetraethylester 4 is obtained.
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