Study On The Synthesis Of Novel Glycoside Latent Aroma Compounds

With the society's stricter requirements for "harm reduction and coke reduction" of cigarette products,everyone has paid extensive attention to flavoring substances for glycosides.The molecular weight of commonly used flavoring materials for cigarettes is relatively small.When it is used in cigarette flavoring,its volatility loss is obvious during storage and use,especially when it is heated at high temperature.This can lead to problems such as short aroma retention time,uneven aroma,and poor flavoring effects.The glycoside latent aroma compounds can supplement the aroma of cigarettes treated by reducing coke and reduce harm,and release aroma components through glycosidic bond breakage,thereby increasing the smoke aroma concentration,eliminating the adverse effects of coke reduction on tobacco aroma to a certain extent,and making the quality of cigarette maintain a relatively stable level.In this paper,a preliminary screening of glycoside synthesis technology was carried out,and it was determined that Koenigs-Knorr method was selected as the process route to synthesize five kinds of compounds ?-pyranoside with a tertiary carbon atom including 1-methyl-1-ethyl-5methylhexane-?-D-glucopyranoside.The conditions such as feed ratio,reaction time,temperature,type and equivalent of alkali were optimized.The optimal synthesis conditions were that the ratio of brominated sugar,alcohol and silver carbonate was 1: 2.00: 1.40,t = 24 h,and the total yields were 56.39%,55.51%,35.65%,30.46%,and 26.68%.And the synthesis of 3,7-dimethyl-6-heptenyl-?-D-glucopyranoside and other four kinds of unsaturated ?-pyranoside.It was determined that the optimal synthesis conditions of bromosaccharide,L-citronellol and silver carbonate at room temperature were 1: 3.00: 1.60 and t = 26 h.The total yield was 49.36%,31.19%,and 34.07 %,55.85%,43.89%.NMR was used to check the correctness of the product.The ten glycosides obtained were sent to an evaluation expert for manual evaluation,which was selected based on comprehensive aroma quality,concentration,strength,miscellaneous gas,irritation,and aftertaste.Six promising glycoside latent substances,such as methyl-1-ethyl-5-methylhexane-?-D-glucopyranoside(3b),dimethyl-5-methylhexaneyl-?-Dglucopyranoside(4b),Dimethyl-phenethyl-?-D-glucopyranoside(5b),3,7-dimethyl-6-heptenyl-?-D-glucopyranoside(8b),3,7-dimethyl-2,6-heptadienyl-?-Dglucopyranoside(9b)and 2-hexenyl-?-D-glucopyranoside(12b)Improve the reference for further research and exploration.