Study On Synthesis Of Vitamin K₂（35） Intermediate

Objective To design and study on a novel synthesis route of1,4-dimethoxy-2-methyl-3-（（2E，6E）-3,7-dimethylnona-2,6-dienyl）naphthalenesulfone which is an important intermediate of vitamin K（235）. And to getits optimized synthetic pr-ocedure.Methods Starting from2-methyl-1,4-naphthoquinone and geraniol, theinterme-diate of Vitamin K₂（35） can be obtained through eight steps such as bromination, reduction, methylation, Grignard reaction, allylic hydroxylation, allylic sulfone substit-ution, etc. Single factor test wasused to optimize a part of the reaction process. The structures of the target compound and some intermediates were confirmed by1H-NMR、13C-NMR and MS.Results The synthesis process of1,4-dimethoxy-2-methyl-3-（（2E，6E）-3,7-dimethylnona-2,6-dienyl）naphthalene sulfone has been completed acco r d i n g t o t h eroute designed, and the target compound was obtained, the total yield was20.5%. The structures of the target compound and the intermediate hasb e e n e s t a b l i s h e dby MS,1H-NMR and13C-NMR.Conclusions The procedure developed has several advantage of convenient oper-ation, low toxicity, facile condition and cheap materials. Theobtained target comp-ound can make the synthesis of vitamin K₂（35） for side chain extension more co-nveniently.