Towards the Synthesis of β-Hydroxy 1,3-Dithiane Derivatives

Abstract

The β-hydroxy dithiane, 3-(1,3-dithiane-2-yl)-1,1-diethoxypropan-2-ol, was synthesized from the versatile synthon 3,3,4,4-tetraethoxybut-1-yne (TEB). 1,1-Diethoxy-3-(2-methyl-1,3- dithian-2-yl)propan-2-ol was successfully formed in low yield (13%) by an alkylation reaction involving the dithiane and MeI in the presence of n-BuLi. An attempt at a silylation reaction using the dithiane failed to produce the trimethylsilyl protected hydroxy derivative. Hydrolysis of the benzyl protected β-hydroxy dithiane was successful (35%) but attempted chain elongation of the corresponding aldehyde using Wittig olefination failed. Alternative procedures for synthesizing 1,1-diethoxybut-3-yn-2-one (TEB-ketone), needed in the formation of the β-hydroxy dithiane, were explored. As a result, a new a three-step method for generating the TEB-ketone was developed. A novel four-step synthesis of the β-hydroxy dithiane from easily available and inexpensive ethyl 2,2-diethoxyacetate is also described.