Zhejiang Petrochemical Valve Co., Ltd.

Jiangsu Ruike Medical Science and Technology Co., Ltd.

Wei Xiang

Zhongyuan Wang

Jianhua Chen

Huaimin Wu

Jingpan Su

Hu Jin

Jingxin Lin

Yijiang Mei

Guangwu Xiang

Rongshui Yang

Fei Nan

Zhaobo Gao

Xiaodong Ma

Aiyi Huang

Meilin Huang

Zhidong Wan

Dawei He

Yongxi Li

Zengle Zhou

The invention relates to the field of pharmaceutical synthesis, in particular to a preparation method of (3R,3aS,6aR)-hexahydrofuro[2,3-b]furan-3-ol derivatives and their intermediates. The preparation method is carried out starting from compound Formula A1.  In the preparation of (3R,3aS,6aR)-hexahydrofuro[2,3-b]furan-3-ol derivatives, the chirality was constructed by enzymatic method, and the products were prepared with high optical purity. The preparation method can be used to produce the key intermediates of (3R,3aS,6aR)-hexahydrofuro[2,3-b]furan-3-ol of darunavir commercially, which is a very economical route suitable for industrial production.

Method for preparing hexahydrofuro-furanol derivative, intermediate thereof and preparation method thereof

An ultra-high temperature (UHT) rigidity seal ball valve that includes an upper cover, a valve cover, a valve body, a valve rod and a ball body. The valve seat is arranged in the valve body; the valve rod penetrates the upper cover and the valve cover sequentially and connects to the ball body; a sealing element is arranged between the upper cover and the valve rod and between the valve cover and the valve rod; the ball body includes a medium channel; a hermetically-sealed cooling cavity encircles the outside of the medium channel of the ball body; a through hole allowing cooling liquid to pass through to the cooling cavity is formed in the valve rod. An accommodating cavity is arranged in the ball body; the through communicates with the accommodating cavity, so that cooling liquid can be introduced to a product when the valve operates at an ultra-high temperature.

Ultra-high temperature rigidity seal ball valve

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Zhejiang, China

Wei Xiang