Synthesis of the Benzo- fused Indolizidine Alkaloid Mimics

• Daniel L. Comins and
• Kazuhiro Higuchi

Beilstein J. Org. Chem. 2007, 3, No. 42, doi:10.1186/1860-5397-3-42

• compounds. Results and Discussion The reaction of various kinds of heteroaryl Grignard reagents with the N-acylpyridinium salt prepared from 4-methoxypyridine (6) and 2-iodobenzoylchloride (7a) was studied (Table 1). The addition of 2-furyl [8], 2-thienyl [9] and 2-pyrrolyl [10][11] Grignard reagents gave N

• results, the reaction of 3-heteroaryl Grignard reagents was also examined (entries 6–9). The 3-furyl [16] and 3-thienyl [17] Grignard reagents were prepared from the corresponding 3-bromo compounds and gave 1f and 1g in moderate yields (entries 6,7). The compounds 1h and 1i were prepared in good yield

• biological activity. The various kinds of N-acyldihydropyridones 1 were conveniently prepared from heteroaryl Grignard reagents and N-acylpyridinium salts. Subsequently, dihydropyridones 1 were converted to 8 by use of an intramolecular Heck cyclization. The chloro- and nitro-substituted acyl chlorides 7

A divergent asymmetric approach to aza-spiropyran derivative and (1S,8aR)-1-hydroxyindolizidine

• Jian-Feng Zheng,
• Wen Chen,
• Su-Yu Huang,
• Jian-Liang Ye and
• Pei-Qiang Huang

Beilstein J. Org. Chem. 2007, 3, No. 41, doi:10.1186/1860-5397-3-41

• of enantiomeric malimide-based synthetic methodologies, [35][36][37][38] we now report concise and highly diastereoselective syntheses of an aza-spiropyran derivative 7 and (1S,8aR)-1-hydroxyindolizidine (ent-3). Results and discussion Previously, we have shown that the addition of Grignard reagents

Pd-catalysed [3 + 3] annelations in the stereoselective synthesis of indolizidines

• Olivier Y. Provoost,
• Andrew J. Hazelwood and
• Joseph P. A. Harrity

Beilstein J. Org. Chem. 2007, 3, No. 8, doi:10.1186/1860-5397-3-8

• phosphites have been reported using Grignard reagents [14]. In addition, 31P NMR studies showed that the addition of 1 equivalent of nBuLi to P(OPri)3 gave a mixture of P(OPri)3 and PBun3 after 15 minutes (See Supporting Information File 1 for details). Interestingly however, we have found PBun3 to be