| Abstract: | The stereochemical course of the formation of the alkyl ether bond in alkyl ether lipids was investigated through the synthesis of stereospecifically labeled acyl R- or S-1-3H]dihydroxyacetone 3-phosphate (DHAP) starting from L-glyceraldehyde. It was demonstrated directly that the formation of the alkyl ether bond results in the stereospecific exchange of the pro-R C-1 hydrogen of DHAP with a proton of water. The configuration of the hydrogen that is retained on C-1 after formation of the alkyl ether bond was also investigated. The alkyl ether lipid was degraded, and the DHAP backbone isolated as glycerol, converted to DHAP via glycerol 3-phosphate and treated with either aldolase or triose phosphate isomerase. The results demonstrated that the retained hydrogen on C-1, which was pro-S in the starting substrate, was pro-S in the product alkyl ether. |
