- Reduction of N,N-Dimethylcarboxamides to Aldehydes by Sodium Hydride–Iodide Composite
-
A new and concise protocol for selective reduction of N,N-dimethylamides into aldehydes was established using sodium hydride (NaH) in the presence of sodium iodide (NaI) under mild reaction conditions. The present protocol with the NaH-NaI composite allows for reduction of not only aromatic and heteroaromatic but also aliphatic N,N-dimethylamides with wide substituent compatibility. Retention of α-chirality in the reduction of α-enantioriched amides was accomplished. Use of sodium deuteride (NaD) offers a new step-economical alternative to prepare deuterated aldehydes with high deuterium incorporation rate. The NaH-NaI composite exhibits unique chemoselectivity for reduction of N,N-dimethylamides over ketones.
- Chan, Guo Hao,Ong, Derek Yiren,Yen, Zhihao,Chiba, Shunsuke
-
-
- Synthesis and biological evaluation of abietic acid derivatives
-
A series of C18-oxygenated derivatives of abietic acid were synthesized and evaluated for their cytotoxic, antimycotic, and antiviral activities. In general, the introduction of an aldehyde group at C18 did improve the resultant bioactivity, while the presence of an acid or alcohol led to less active compounds.
- Gonzalez, Miguel A.,Correa-Royero, Julieth,Agudelo, Lee,Mesa, Ana,Betancur-Galvis, Liliana
-
experimental part
p. 2468 - 2472
(2009/12/03)
-
- Synthesis and characterization of abietadiene, levopimaradiene, palustradiene, and neoabietadiene: Hydrocarbon precursors of the abietane diterpene resin acids
-
The abietane diterpenes - abietadiene, levopimaradiene, palustradiene, and neoabietadiene (1b-4b) - were prepared from the corresponding resin acids by diazomethane esterifications, LiAlH4 reductions, tosylations, and Zn/NaI reductions. Abietadiene was also obtained less efficiently by catechol borane reduction of abietadienal tosylhydrazone and Li/NH3 reduction of its 18-phenylthio derivative. These conjugated dienes were characterized by chromatographic properties (HPLC, TLC, GC), MS fragmentation patterns, optical rotations, and UV, IR, 1H NMR, and 13C NMR data. Assignments for the 1H and 13C NMR spectra were made by COSY, DEPT, HMQC, HMBC, NOE data, H-H coupling analysis, and comparisons with literature data. The four diterpenes were identified as cyclization products of recombinant abietadiene synthase, supporting their likely role in the biosynthesis of the abietane resin acids in conifer oleoresin.
- Lee, Hyung-Jae,Ravn, Matthew M.,Coates, Robert M.
-
p. 6155 - 6167
(2007/10/03)
-
- Conversion of Abietic Acid into Analogues of Ambergris Odorants
-
The conversion of methyl abietate (16) into (42) and (43), analogues of the known amber odorants (1) and (2), is reported.
- Cambie, Richard C.,Rutledge, Peter S.,Ryan, Glen R.,Strange, Gary A.,Woodgate, Paul D.
-
p. 867 - 881
(2007/10/02)
-