High chemoselectivity in the phenol synthesis

• Matthias Rudolph,
• Melissa Q. McCreery,
• Wolfgang Frey and
• A. Stephen K. Hashmi

Beilstein J. Org. Chem. 2011, 7, 794–801, doi:10.3762/bjoc.7.90

• PMB-protected aldehyde 43 (Scheme 11) [45]. The resulting furfuryl alcohol 44 was then propargylated to give 45. The deprotection was however, problematic. Treatment of the latter with cerium ammonium nitrate led to decomposition. Only with DDQ was the desired alcohol 39 obtained in moderate yield

Diels- Alder reactions using 4,7-dioxygenated indanones as dienophiles for regioselective construction of oxygenated 2,3-dihydrobenz[f]indenone skeleton

• Natsuno Etomi,
• Takuya Kumamoto,
• Waka Nakanishi and
• Tsutomu Ishikawa

Beilstein J. Org. Chem. 2008, 4, No. 15, doi:10.3762/bjoc.4.15

• ). Intramolecular Friedel-Crafts reaction of 2,5-dimethoxybenzenepropanoic acid (15) and the 4-brominated derivative 16 [31], by a procedure modified from the synthesis of 4 [23], afforded the corresponding indanones 17 and 18. Cerium ammonium nitrate (CAN) oxidation [32] of indanone 17 smoothly afforded

A convenient allylsilane- N-acyliminium route toward indolizidine and quinolizidine alkaloids

• Roland Remuson

Beilstein J. Org. Chem. 2007, 3, No. 32, doi:10.1186/1860-5397-3-32

• carried out as shown in Scheme 2. Reaction of (R)-2 with succinic anhydride and then with acetyl chloride in refluxing toluene gave imide 3, then, 3 was reduced into ethoxylactam 4. In the next step, 4 was treated with two equivalents of the cerium reagent derived from trimethylsilymethylmagnesium

• ' procedure from ethyl crotonate and respectively (R)- and (S)-N-benzyl-α-methylbenzylamine. [17] Reaction of 23a with succinic anhydride and then with acetyl chloride gave imide 24a, it was then reduced into ethoxylactam 25a. Compound 25a was treated with the cerium reagent derived from

• trimethylsilylmagnesium chloride and cerium chloride. The mixture was then hydrolysed with 1N HCl to give methylenindolizidinones 26a and 26b in a 4:1 ratio. These diastereomers could not be separated. According to Scheme 6, in the first step the reduction of the lactam functional group of cyclisation products 26a and

Investigation of acetyl migrations in furanosides

• O. P. Chevallier and
• M. E. Migaud

Beilstein J. Org. Chem. 2006, 2, No. 14, doi:10.1186/1860-5397-2-14

• ribosides, acyl migration could be prevented when desilylation was catalysed by cerium ammonium nitrate. Introduction Over the years, a number of methods aimed at achieving chemoselective acylation of carbohydrates have been developed.[1][2][3] In addition to the challenges encountered in the selective