An efficient synthetic method for the allylic sulfone 2 containing a conjugated triene moiety has been proposed involving i) coupling of allylic sulfones 4 with the C 5 bromoallylic sulfide 5, ii) base-promoted dehydrosulfonation in the presence of allylic sulfide, and iii) selective oxidation of the resulting trienyl sulfide to the corresponding sulfone. Total synthesis of lycopene starting from the C 15 allylic sulfone 2b has been described, where the new C 10 bis(chloroallylic) sulfone 11 proved to be a useful substitute for the C 10 bis(chloroallylic) sulfide 3, which did not require the problematic chemoselective sulfur oxidation in a conjugated polyene.Introduction. ± Carotenoids such as b-carotene (1a) and lycopene (1b) are characterized by long conjugated polyene chains that show distinctive red colors and are ideally utilized as nonhazardous dyes for foodstuffs. High reactivity of these polyenes with activated carcinogenic oxygen or radicals provides carotenoids with prophylactic effects against certain cancers of the pancreas, the mouth, and the bladder, etc.[1]. Among the numerous approaches that have appeared in the literature to build the conjugated polyene chains of carotenoids [2], methods based on acetylide coupling/ partial hydrogenation [3] and Wittig olefination [4] have been the two main synthetic approaches. The Julia sulfone olefination protocol [5], which has been applied to retinol synthesis [6], is presumed to be the best method to produce double bonds with the (E)-configuration [7]. We have introduced the C 10 bis(chloroallylic) sulfide 3 as a stable substitute for the highly unstable 1,8-dichloro-2,7-dimethylocta-2,4,6-triene, and successfully accomplished total syntheses of b-carotene (1a) and lycopene (1b) based on the Julia sulfone-olefination protocol [8]. To generalize this process with C 10 bis(chloroallylic) sulfide 3 for carotenoid syntheses, an efficient method should be devised to build allylic sulfones containing conjugated CC bonds such as 2 (Scheme 1). We herein report our strategy to synthesize allylic sulfones comprising a conjugated triene moiety and total synthesis of lycopene [9] by means of the allylic sulfone 2b.

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New C5 sulfone building blocks containing a masked polar end group have been devised for the efficient synthesis of carotenoids with polar termini. Chemoselectivity or the regiochemical issue of the highly functionalized units has been carefully addressed depending on the soft or hard nature of electrophiles. These building blocks have been successfully applied to the syntheses of crocetin derivatives, crocetin dial and the novel crocetin dinitrile.

Web content mining describes the classification, clustering, and attribute analysis of a large number of text documents and multimedia files on the web. Special tasks include retrieval of data from the Internet search engine tool W; structured processing and analysis of web data. Today’s blog analysis has security concerns. We do experiments to investigate its safety. Through experiments, we draw the following conclusions: (1) Web log extraction can use efficient data mining algorithms to systematically extract logs from web servers, then determine the main access types or interests of users, and then to a certain extent, based on the discovered user patterns, analyze the user’s access settings and behavior. (2) No matter in the test set or the mixed test set, the curve value of deep mining is very stable, the curve value has been kept at 0.95, and the curve value of fuzzy statistics method and quantitative statistics method is stable within the interval of 0.90–095. The results also show that the data mining method has the highest identification accuracy and the best security performance. (3) Web usage analysis requires data abstraction for pattern discovery. This data abstraction can be achieved through data preprocessing, which introduces different formats of web server log files and how web server log data is preprocessed for web usage analysis. One of the most critical parts of the web mining field is web log mining. Web log mining can use powerful data mining algorithms to systematically mine the logs in the web server and then learn the user’s access or preferred interests and then conduct a certain degree of user preferences and behavior patterns according to the discovered user patterns. Based on the above analysis, the current web log analysis is faced with security problems. We conduct experiments to study to verify the security performance of web logs and draw conclusions through experiments.

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