Reductive removal of halo and mesyloxy groups with a copper(I) complex

Chiral Synthesis of (R)-(-)(5Z)-4-Hydroxy-5-tetradecenoic Acid-4-lactone

“…Treatm ent of the tosylate 9 with either sodium borohydride in HMPA at room tem perature and 100 °C or lithium triethyl borohydride in TH F at reflux resulted in only oxygen-sulfur bond cleavage instead of displacement. The use of the C u'H complex, reported by Masa- via free access mune and coworkers [42], in T H F resulted in oxygen-sulfur bond cleavage as well. In spite of the low yield experienced in the deoxygenation reac tion of 8, conditions were established for the mild hydrolysis of 10, using 0.01 N hydrochloric acid in TH F:H 20 , 1:1 at 5 5 -6 0 °C, which gave 11 in good yield.…”

“…Removal of the solvent in vacuo gave 11 (130 mg, 76%) as an oil, which was chromatographically homogeneous and was used directly. Oxidation of 11 was accomplished with the Collins reagent, dipyridine-chromium (Vl)-oxide (1.4 g, 8.8 mmol) in CH 2C12 (20 ml), prepared as described [42]. The mixture was stirred at room tem perature for 2 h, filtered through a short pad of silica gel and the solvent removed to give a residue which, after column chromatography with ether/petroleum ether (1:3), …”

Lithium aluminium hydride reduction of some triarylvinyl bromides and acetates catalyzed by some transition metal chlorides

“…The conversion of organic halides to the corresponding hydrocarbons, which is an important synthetic procedure, has been accomplished with organolithium-copper complexes, titanium chloride -magnesium complexes (1)(2)(3)(4), and by the combination of lithium aluminium hydride (LAH) and transition metal chlorides (5). The results with the latter system indicate that LiA1H4/NiCl2, in particular, is capable of reducing primary, cyclic, and aromatic halides in quantitative yields.…”

Metabolites of bird's nest fungi. Part 8. Some minor metabolites of Cyathus helenae and some correlations among the cyathins

“…Treatment of 19 with an excess of the reagent prepared from LiAlH(OCH,), and CuI in T H F (9) gave allocyathin B, methyl acetal (20) in 76% yield. Acid catalyzed hydrolysis of the methyl acetal 20 gave allocyathin B, (3).…”