3 results about "Diketene" patented technology

The application discloses a method for synthesizing (R)-( - )-1,3-butanediol by a one-step method of diketene, which uses a chiral ruthenium complex as a catalyst and a Bronsted acid as an assistant to make the diketene react by a one-step method under certain temperature and hydrogen pressure conditions to obtain (R)-( - )-1,3-butanediol. The method solves the problems of high cost, large catalyst consumption and difficult product separation in the prior art for preparing (R)-( - )-1,3-butanediol, and can asymmetrically hydrogenate the carbonyl group of the substrate diketene at low cost and with a small amount of catalyst, simultaneously reduces the ester group and opens the ring to obtain (R)-( - )-1,3-butanediol. The method has simple reaction operation and simple catalyst preparation, the yield of the target product and ee value are both above 98%, meanwhile, the catalyst can be repeatedly used, the cost is greatly reduced, and the method has the potential for industrial application.

The application provides a method for preparing beta-butyrolactone through asymmetric hydrogenation of diacetylene ketone, which is prepared through catalyzing asymmetric hydrogenation of diacetylene ketone under a hydrogen atmosphere by using a metal active component and a pyridine ring phosphine ligand as a catalyst. The method uses a hydroxyl-containing nitrogen heterocyclic phosphine ligand as a ligand, and a metal such as palladium, rhodium or ruthenium as an active metal, so that the conversion rate and selectivity of the reaction are improved, the stability of the catalyst is good, and the catalyst can be used multiple times. The synthesis route of the catalyst used in the method is short, the yield is high, the number of times of reusing is large, and the method has a good cost advantage.

The application discloses a full synthesis method of cephinold H and fortalpinoid C, comprising the following steps: taking natural product cephanolide B as a raw material, carrying out oxidative de-arrangement and acetylation to obtain a dienone compound, then carrying out ring expansion rearrangement to obtain natural product cephinold H as a secondary product, then introducing an occupying group (Br or Cl atom) to improve the regioselectivity of the ring expansion rearrangement, so that a ring expansion product substituted with a halogen atom (Br or Cl atom) is obtained in a high proportion, then removing the halogen atom (Br or Cl atom) under a palladium catalytic reduction condition to obtain natural product cephinold H, then oxidizing cephinold H by selenium dioxide and reducing by sodium borohydride to obtain natural product fortalpinoid C with opposite configuration, and finally inverting the configuration of the hydroxyl group through a Mitsunobu reaction, so that the chemical synthesis of fortalpinoid C is realized, and the synthesis route has the advantages of simplicity, high efficiency, simple operation, low cost and the like, and is suitable for the mass synthesis of cephinold H and fortalpinoid C, and provides an important material basis for the bioactivity evaluation of the two products.