已完成(-)-schulzeine B(一种具有强大的抗糖尿病活性的海洋天然生物碱)的正式合成。苯并[ a ]喹啉齐丁-4-酮是舒尔西因(A–C)的常见骨架。(-)-舒尔西丁B在C-3碳上具有(S)-立体异构中心。由(2-溴-3,5-二羟基苯基)乙腈分17步有效地制备了手性(3 S,11b S)-3-氨基-9,11-二甲氧基苯并[ a ]喹啉亚丁-4-一)由HClO 4催化的脱水分子内胺化;和(ii)脯氨酸或硼酸催化的反式环酰胺化反应,用于构建δ-内酰胺环。
Enantioselective Synthesis of Schulzeines B and C via a β-Lactone-Derived Surrogate for Bishomoserine Aldehyde
摘要:
Enantioselective syntheses of the glucosidase inhibitors schulzeines B and C were achieved by employing a Pictet-Spengler reaction of a beta-lactone-derived masked bishomoserine aldehyde. Subsequent Corey-Link reaction unveiled an alpha-azido acid enabling cyclization to the delta-lactam fused tetrahydroisoquinoline. An efficient synthesis of the trisulfate-bearing side chain featured a Noyori hydrogenation and a Sharpless dihydroxylation. An unexpected reaction of a pendant amine during a Corey-Link process opens avenues for the synthesis of proline and related amino acid derivatives.