Department of Chemistry MS 015, Brandeis University, Waltham, Massachusetts 02454-9110, USA.
Org Lett. 2010 Apr 2;12(7):1600-3. doi: 10.1021/ol100333d.
A model for the spiroiminal moiety of marineosins A and B was prepared starting from methylvalerolactone. Addition of vinylmagnesium bromide, protection of the alcohol, and reaction of the vinyl ketone with a protected pyrrole-2-carbonitrile N-oxide gave an isoxazoline. Hydrogenolysis of the N-O bond with Raney nickel gave a keto imine that cyclized to a hemi-iminal. O-Methylation, acid-catalyzed cleavage of the TES group and spiroiminal formation, and deprotection completed a seven-step synthesis.
从甲基戊内酯出发，制备了海洋霉素 A 和 B 的螺环亚胺部分的模型。加成乙烯基溴化镁，保护醇，然后将乙烯酮与保护的吡咯-2-腈 N-氧化物反应，得到异恶唑啉。用雷尼镍氢化 N-O 键得到酮亚胺，该酮亚胺环化得到半亚胺。O-甲基化、TES 基团的酸催化裂解和螺环亚胺的形成，以及脱保护完成了七步合成。
