Synlett 2008(12): 1829-1832  
DOI: 10.1055/s-2008-1078572
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

A Catalyst-Free, Convenient Construction of Eight-Membered [1,4]Oxazocane-5,8-dione Heterocycles from Aminoethanols with Divinyl Succinate

Wan-Qin Chen, Qing-Yi Zhang, Bo-Kai Liu, Qi Wu, Xian-Fu Lin*
Department of Chemistry, Zhejiang University, Hangzhou, 310027, P. R. of China
Fax: +86(571)87952618; e-Mail: llc123@zju.edu.cn;
Further Information

Publication History

Received 25 March 2008
Publication Date:
02 July 2008 (online)

Abstract

A convenient protocol for the synthesis of [1,4]oxazocane-5,8-dione heterocycles by direct cyclization using 2-substituted aminoethanols and divinyl succinate without any catalysts and additives was established. This strategy is quite simple and effective to obtain eight-membered rings incorporating lactone and lactam functional groups.

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Typical Procedure for the Synthesis of 3,3-Dimethyl-[1,4]oxazocane-5,8-dione (4a)
2-Amino-2-methyl-1-propanol (20 mmol) was dissolved in DMSO (20 mL) and the divinyl succinate (24 mmol) was added. The reaction mixture was stirred at 110 ˚C and monitored by TLC. Upon completion of the reaction, the reaction gave a yellow solution which was purified by column chromatography (hexane-EtOAc, 1:1) to obtain the product. ¹H NMR (500 MHz, CDCl3): δ = 3.81 (d, 2 H, J = 5.6 Hz), 3.57 (br s, 1 H), 2.66 (s, 4 H), 1.48 (s, 6 H) ppm. ¹³C NMR (100 MHz, CDCl3): δ = 179.2, 69.2, 62.8, 28.6, 22.1 ppm. ESI-MS: m/z = 193.8 [M + Na]+. IR: 3440 (NH amide), 1772 (C=O amide), 1696 (C=O ester) cm.