Darzina Madara, Lielpetere Anna, Jirgensons Aigars
Latvian Institute of Organic Synthesis Aizkraukles 21, Riga, LV-1006, Latvia.
Faculty of Natural Sciences and Technology, Riga Technical University, 3 P. Valdena Street, Riga LV-1048, Latvia.
Beilstein J Org Chem. 2025 Aug 29;21:1737-1741. doi: 10.3762/bjoc.21.136. eCollection 2025.
Alloc-protected furfuryl amino alcohols derived from furfural and ʟ- or ᴅ-valinol were subjected to Torii-type ester electrosynthesis to obtain the corresponding unsaturated esters. These served as key intermediates to prepare ()- and enantioenriched unsaturated amides by -Alloc deprotection which induced concomitant methoxymethyl group cleavage, to- rearrangement, and isomerization of the double bond. An oxazoline ring formation in the resulting unsaturated amides provided the corresponding enantioenriched vinyloxazoline. The reactivity of the electron-deficient double bond in the vinyloxazoline was explored in several reactions. Out of these, the aza-Diels-Alder reaction with TsNCO was successful, leading to a highly diastereoselective formation of an oxazolo[3,2-]pyrimidine derivative.
将由糠醛与L-或D-缬氨醇衍生的Alloc-保护的糠基氨基醇进行托里型酯电合成，以获得相应的不饱和酯。这些不饱和酯作为关键中间体，通过-Alloc脱保护制备（）-和对映体富集的不饱和酰胺，该脱保护过程会引发甲氧基甲基基团的伴随裂解、重排以及双键的异构化。所得不饱和酰胺中恶唑啉环的形成提供了相应的对映体富集的乙烯基恶唑啉。在几个反应中研究了乙烯基恶唑啉中缺电子双键的反应活性。其中，与TsNCO的氮杂狄尔斯-阿尔德反应成功进行，导致恶唑并[3,2-]嘧啶衍生物的高非对映选择性形成。
