330151-69-4

Upstream product

• 520-43-4 2-hydroxy-4-methoxy-6-methyl-benzoic acid methyl ester 
• 3587-60-8 Benzyloxymethyl chloride 
• 221356-83-8 (R)-5,6-dihydro-4-methoxy-6-methyl-2H-pyran-2-one 
• 330151-68-3 methyl 2-benzyloxymethoxy-4-methoxy-6-methylbenzoate 

Downstream Products

• 70477-26-8 (+)-semivioxanthin 

Relevant academic research and scientific papers

Total synthesis of (R)- and (S)-semi-vioxanthin

Compounds (R)- and (S)-semi-vioxanthin 2 were synthesized by a tandem Michael reaction of orsellinate 3 and the chiral Michael acceptors 4. The key step for the formation of lactone (R)-4. is a regio- and enantioselective, enzyme-catalyzed reduction of tert-butyl 3,5-dioxohexanoate (5) by an alcoholdehydrogenase from Lactobacillus brevis. Compound (S)-4 was synthesized by the Claisen condensation of tert-butyl acetate and ethyl (S)-3-hydroxy-butanoate (8). Cleavage of the benzyloxymethyl groups in the protected (R)- and (S)-semi-vioxanthins was achieved by hydrogenolysis to afford (R)-2 and (S)-2, respectively.