Synthesis of novel symmetrical, single-chain, diacetylene-modified bolaamphiphiles with different alkyl chain lengths
作者:Simon Drescher、Katrin Helmis、Andreas Langner、Bodo Dobner
DOI:10.1007/s00706-010-0255-y
日期:2010.3
General syntheses of novel symmetrical, single-chain, diacetylene-modified bolaphospholipids have been carried out in five steps. For the omega-alkynols, which have an important role as key intermediates, three different synthetic approaches were comprehensively investigated. For the final synthesis it is suggested that (1) alkylation of lithium (trimethylsilyl)acetylide with tetrahydropyranyl-protected omega-bromoalcohols, followed by (2) cleavage of the trimethylsilyl moiety and the tetrahydropyranyl protecting group, and (3) copper(II)-catalyzed Eglinton coupling is the best strategy for obtaining diacetylene-modified alkane-1,omega-diols, because higher yields were obtained while avoiding the formation of by-products. Moreover, conversion of the diols into bipolar phospholipids was achieved by bis-phosphorylation with beta-bromoethylphosphoric acid dichloride and subsequent quaternization with trimethylamine or dimethylamine. Finally, spectral data are presented for novel single-chain, diacetylene-modified bolaphospholipids with promising potential as starting molecules in the formation of polymerizable and, thus, thermostable nanofibers.