The present invention relates to pyran-fused ring compounds, preparation methods thereof and use thereof, especially to pyran-fused ring compounds usable for preparing Halichondrin, Eribulin, or analogues thereof, preparation methods thereof and use thereof. Use of any of the compounds of formula (I) to (XIII) of the present invention in preparation of Halichondrin B, Eribulin, analogues thereof or C1-C13 moieties thereof. Provided in the present invention are intermediates usable for preparing Halichondrin B, Eribulin, or analogues thereof, especially the key product of C1-C13 moieties, preparation methods thereof and use thereof. The starting material for the synthesis pathway of the present invention is inexpensive and readily available with sustainable source and reliable quality. Since the structural characteristics of the reactants of theirself are made full use in choosing the method of constructing the chiral centers, the efficiency in the synthesis is considerably increased, the difficulty in and the risk on quality control of the product are reduced; and using a highly toxic and expensive high-valent osmium catalyst is avoided, which have the cost and environmental friendliness significantly improved.

The present disclosure relates to a compound and a preparation method and application thereof, the compound having a chemical structure formula of:

##STR00001##

wherein M in the formula is selected from a group consisting of CF.sub.3 or CF.sub.2H, and R.sub.1, R.sub.2, and R.sub.3 are each independently selected from a group consisting of aryl, heteroaryl, and alkyl. The compound provided by the present disclosure can be used as a trifluoroethanolation reagent or difluoroethanolation reagent as synthetic intermediates of many organic compounds, and some of the compounds have pharmaceutical activity. The preparation steps of such compounds are simplified, with mild synthesis conditions and wide applicability of substrates.

A perfluoro(poly)ether group containing silane compound represented by the formula (1a) or the formula (1b):
A-Rf—X—SiQ.sub.kY.sub.3-k  (1a)
Y.sub.3-kQ.sub.kSi—X—Rf—X—SiQ.sub.kY.sub.3-k  (1b)
as defined herein. Also disclosed is a process for producing the compound, a surface-treating agent containing the compound, a pellet containing the surface-treating agent and an optical member including a base material and a layer formed on a surface of the base material from the compound.

A perfluoro(poly)ether group containing silane compound represented by the formula (1a) or the formula (1b):
A-Rf—X—SiQ.sub.kY.sub.3-k  (1a)
Y.sub.3-kQ.sub.kSi—X—Rf—X—SiQ.sub.kY.sub.3-k  (1b)
as defined herein. Also disclosed is a process for producing the compound, a surface-treating agent containing the compound, a pellet containing the surface-treating agent and an optical member including a base material and a layer formed on a surface of the base material from the compound.

The invention relates to new intermediates in the synthesis of Eldecalcitol and to processes for the preparation of said intermediates and of Eldecalcitol.

An intermediate compound is prepared and used for the synthesis of halichondrin B, eribulin or an analog thereof, particularly a structural fragment C27-C35 thereof. The starting materials of the synthetic route are readily available, and the optical purity of the starting materials can be ensured, so that the optical purity of the structural fragment C27-C35 in halichondrin B, eribulin or the analog thereof is ensured. Steps for constructing a chiral center of the structural fragment C27-C35 feature higher diastereoselectivity and yield, in particular preparation methods of compounds of formulae (X), (XI), (XVI) and (XV). By-products of partial reactions can be removed only by recrystallization, which results in easy purification and significant reduce in cost.

Provided is a method for producing a silane compound, which does not produce corrosive substances such as acids, does not use organic solvents and which contributes to a reduction in environmental load. This method for producing a silane compound has D) a siloxane decomposition step for heating a mixture containing: a siloxane compound A), which is a cyclic siloxane compound A-1) represented by formula (1), a linear siloxane compound A-2) represented by formula (2) and/or a silsesquioxane compound that is represented by formula (3) and has a siloxane bond as a main chain skeleton; a carbonate compound B) including at least one of a diaryl carbonate, a dialkyl carbonate and a monoalkylmonoaryl carbonate; and a basic compound catalyst C). The step D) further includes subjecting the siloxane compound A) to alkoxylation and/or aryloxylation. (In the formulae, R.sup.1 to R.sup.5, X, n, m and pare as described in the description of the present application.)

##STR00001##

Processes for preparing latanoprostene bunod and an intermediate prepared from the process. Also latanoprostene bunod compositions having high-purity latanoprostene bunod.

This organopolysiloxane composition, when cured at room temperature by moisture in the atmosphere, provides a silicone rubber cured product having good self-adhesiveness to a magnesium alloy. The organopolysiloxane composition contains (A) an organopolysiloxane having a hydroxy group and/or a hydrolysable silyl group at both ends of the molecular chain, (B) an organic silicon compound other than (A) and (C), having at least three hydrolysable groups bonded to a silicon atom per molecule, and/or a partial hydrolysis-condensation product thereof, and (C) a silane coupling agent having a specific molecular structure having a carboxylic acid silyl ester bond. Furthermore, a novel compound, having an alkoxysilyl group and a carboxylic acid silyl ester group per molecule, can have improved adhesiveness/bonding properties with respect to a base material due to the effect of carboxylic acid after hydrolysis thereof.

A method for preparing a hydrocarbylhydrocarbyloxysilane of formula R.sub.aH.sub.pSi(OR)(4.sub.-a-b), where each R is independently a hydrocarbyl group and subscript a is 1 to 4 and subscript b is 1 to 2 is disclosed. The method includes heating ingredients including a hydrocarbyl carbonate and a source of silicon and catalyst. The method can be used to make dimethyldimethoxysilane.