The title compound 3, a useful intermediate in the synthesis of carbocyclic analogs of nucleosides was synthesized from (-)-β-pinene (4) in seven steps: oxidation of 4 to (+)-nopinone (5); Beckmann rearrangement of the oxime-O-sulfonic acid of 5 to the bicyclic lactam 7 (a two-step procedure via oxime 6 is also described); hydrolytic ring opening of 7 to form amino acid • HCl 8; and reduction of the corresponding protected methyl ester 10 followed by deprotection. Overall yield, 67% from lactam 7.
标题化合物 3 是合成核苷碳环类似物的有用中间体,由 (-)-δ
蒎烯 (4) 经过七个步骤合成:4 氧化为 (+)-nopinone (5);5 的
肟-O-
磺酸贝克曼重排为双环内酰胺 7(也描述了通过
肟 6 的两步法);7 的
水解开环形成
氨基酸 - HCl 8;还原相应的受保护甲酯 10,然后进行脱保护。内酰胺 7 的总收率为 67%。