The invention relates to the field of pharmaceutical synthesis, in particular to the preparation method of hexahydrofuro-furanol derivative, intermediates thereof and preparation methods thereof. The preparation methods comprises the steps of halogenation reaction, acylation reaction, enzymatic reduction reaction, reaction with amine compounds, reduction ring closure reaction (A1, A2, B, Cp1, C.sub.L, Cf)

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wherein, R.sub.1, R.sub.2, R.sub.3 are hydrogen or hydroxy protecting groups; R.sub.4 and R.sub.5 are the same or different and are phenyl, alkyl or substituted phenyl. In the preparation process of hexahydrofuro-furanol derivatives, the chirality is constructed by enzymatic method, and the product can be prepared with very high optical purity by adopting such technical means. The preparation method can be used to prepare the key intermediate, (3R, 3aS, 6aR)-hexahydrofuro[2,3-b]-3-ol, of Darunavir, in commercial production, which is a very economical route suitable for industrial production.

The present invention relates to compounds and their use in the prophylactic and/or therapeutic treatment of pulmonary fibrosis and/or related conditions.

The present invention relates to compounds and their use in the prophylactic and/or therapeutic treatment of pulmonary fibrosis and/or related conditions.

The invention provides novel methods for preparing indolinobenzodiazepine dimer compounds and their synthetic precursors.

The invention provides novel methods for preparing indolinobenzodiazepine dimer compounds and their synthetic precursors.

The present invention provides compounds, compositions thereof, and methods of using the same.

The present invention provides compounds, compositions thereof, and methods of using the same.

The present invention relates to compounds and their use in the prophylactic and/or therapeutic treatment of pulmonary fibrosis and/or related conditions.

The present invention relates to compounds and their use in the prophylactic and/or therapeutic treatment of pulmonary fibrosis and/or related conditions.

A synthetic nicotine composition comprising synthetic nicotine, a synthetic nicotine salt and a synthetic nicotine derivative, wherein the synthetic nicotine, the synthetic nicotine salt, and the synthetic nicotine derivative are in mass percentage; the synthetic nicotine accounts for 1-20%, the synthetic nicotine salt accounts for 30-70%, and the synthetic nicotine derivative accounts for 20-50%; and the synthetic nicotine is one or more of S-nicotine and a mixture of R-nicotine containing a racemate and S-nicotine. The synthetic nicotine, synthetic nicotine salt and synthetic nicotine derivative according to the present invention are proportionally mixed to prepare an existing synthetic nicotine product, which relieves the problem of the impact of impurities in natural extracted nicotine products causing an unpleasant smell, a bitter taste and a strong volatility, and can be used in the fields of low temperature heat-not-burn products, snuff, electronic cigarettes, nicotine release patches, insecticides, herbicides, microbicides, drug synthesis, etc.