Triphenyl(3,4,5-trimethoxybenzyl)phosphonium bromide → 3-Methyl-6-[(z)-2-(3,4,5-trimethoxyphenyl)vinyl]-1,2-di(tert-butyldimethylsilyloxy)benzene

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A suspension of 3,4,5-trimethoxybenzyltriphenylphosphonium bromide (1.77 g, 3.4 mmol) in tetrahydrofuran (40 mL) was cooled to 0° C. and butyllithium (2.1 mL of a 1.6 N solution in hexane, 3.39 mmol) was added dropwise. The brick red solution was stirred at 0° C. for 20 min, then cooled to −78° C. and a solution of 16 (0.86 g, 2.26 mmol) in tetrahydrofuran (15 mL) was added dropwise. The temperature was allowed to rise to room temperature overnight, than the reaction was poured into brine (100 mL, containing 5 mL of 1 n HCl) and extracted twice with tert-butylmethyl ether (ca 100+50 mL). The combined organic extracts were washed with brine, dried over sodium sulphate and the solvent removed under reduced pressure to give a crude which was purified by column (cyclohexane:AcOEt 9:1) to give 0.6 g of 17:

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