| 摘要 |
Prepn. of symmetrical vicinal diols R. CHOH. CHOH.R (I) in which R is 1-12C alkyl, comprises (1) reacting an aldehyde RCHO (II) with (CH3)3SiCl in the presence of Li in an inert organic solvent at -10 to -50 degrees C to give a bis-trime-thylsilyloxyalkane R. CH(OSi(CH3)3). CH(OSi(CH3)3).R (III), and (2) hydrolysing the (III) to (I).The process is pref. carried out in THF or dimethoxyethane (IV), and the hydrolysis is accomplished e.g. with aq. HCl in the presence of a low alcohol such as (m)ethanol. The process proceeds in high yield (e.g.>90% theory) with low by-product formation.
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