Improved preparation of racemic 1,2,3,6,7,8,11,12,13-nonamethoxy-10,15-dihydro-5H-tribenzo[a,d,g]cyclononene

Yongliang Ding,Bogang Li,Guolin Zhang

doi:10.3998/ark.5550190.0008.e30

Abstract

Racemic 1,2,3,6,7,8,11,12,13-nonamethoxy-10,15-dihydro-5H-trbibenzo [a,d,g] cyclononene was prepared via trimerization of 3,4,5-trimethoxybenzyl alcohol catalyzed by Lewis acids such as AlCl3, ZnCl2, FeCl3 and SnCl4 in chlorinated solvents. The reaction proceeded smoothly in dichloromethane with SnCl4 as catalyst and gave 54% yield. Some open chain oligomers were also obtained.

Highlights

Functionalized cyclotriveratrylenes (CTV), referred as tribenzocyclononene (TBCN), have attracted much attention because of their rigid cone shaped frame and chiroptical properties.1–2 1,2,3,6,7,8,11,12,13-Nonamethoxy-10,15-dihydro-5H-trbibenzo[a,d,g]cyclononene (NDTC) was first isolated when Bosh attempted to couple 3,4,5-trimethoxybenzylmagnesium chloride and 1,3,4-trimethylpyridium iodide.[3]
NDTC is usually prepared by trimerization of 3,4,5-trimethoxybenzyl alcohol in the presence of H2SO41 or bentonite-clay[6] with yields less than 12%
In our attempt to couple 3,4,5-trimethoxybenzyl acetate and benzoyl chloride in the presence of AlCl3 in CH2Cl2, NDTC was obtained in 20% yield

Summary

Introduction

Functionalized cyclotriveratrylenes (CTV), referred as tribenzocyclononene (TBCN), have attracted much attention because of their rigid cone shaped frame and chiroptical properties.1–2 1,2,3,6,7,8,11,12,13-Nonamethoxy-10,15-dihydro-5H-trbibenzo[a,d,g]cyclononene (NDTC) was first isolated when Bosh attempted to couple 3,4,5-trimethoxybenzylmagnesium chloride and 1,3,4-trimethylpyridium iodide.[3]. In our attempt to couple 3,4,5-trimethoxybenzyl acetate and benzoyl chloride in the presence of AlCl3 in CH2Cl2, NDTC was obtained in 20% yield.

Results

Conclusion