The present invention provides compounds of formula (I): wherein W is independently selected from the group consisting of H, F, Cl, Br and I; 10 X is independently selected from the group consisting of H, F, Cl, Br, I, CW.sub.3 and OR on the basis that at least one X is OR; R is independently selected from the group consisting of C(O) (CH.sub.2 ).sub.m(CF.sub.2 ).sub.nY and CW.sub.2C(CW.sub.2OC(O)(CH.sub.2 )m(CF.sub.2 )nY).sub.3; m is an integer from 0 to 2; 15 n is an integer from 2 to 8; Y is C(Z).sub.3; and Z is independently selected from the group consisting of H, F, Cl, Br and I. Such compounds may be utilised as lubricants, for example in heat transfer compositions.

Provided is a polyol ester base stock composition with reduced odor and volatility. The polyol ester back stock composition does not include C5 acid. More particularly, the polyol ester base stock includes the reaction product of: (a) a polyol represented by the formula R(OH).sub.n wherein R is an aliphatic or a cyclo-aliphatic hydrocarbyl group and n is at least 2, and (b) a mixture of monocarboxylic acids comprising at least one linear acid selected from the group consisting of between C6 to C10 acids and at least one branched C6 acid, wherein the amount of C6 to C10 acids is at least 55 wt. % and the amount of the at least one branched C6 acid is 45 wt. % or less, based upon the total amount of said mixture of monocarboxylic acids. The polyol ester base stock is particularly suited for aviation turbine oils.

A method for preparing a partially fluorinated ester comprising acyl and alkoxy groups wherein the acyl group comprises a branched or linear fluorine containing C.sub.3-C.sub.8 group with one of the structures:

##STR00001##

wherein X and Y are independently selected from: H, CH.sub.3, F, CI, CH.sub.2F, CF.sub.3, OCF.sub.3, OCH.sub.2CF.sub.3, OCH.sub.2CF.sub.2CHF.sub.2 and CH.sub.2CF.sub.3 (wherein both X and Y cannot be H) comprising reacting an unsaturated halocarbon:

##STR00002##

wherein A and B are independently selected from the group comprising H, CH.sub.3, F, CI, CH.sub.2F, CF.sub.3, OCF.sub.3, OCH.sub.2CF.sub.3, OCH.sub.2CF.sub.2CHF.sub.2 and CH.sub.2CF.sub.3 (wherein both A and B cannot be H) with carbon monoxide and an alcohol, in the presence of a catalyst.

Provided is a fluorine-containing ether compound represented by the following formula. R.sup.1R.sup.2CH.sub.2R.sup.3[CH.sub.2R.sup.4CH.sub.2R.sup.3].sub.nCH.sub.2R.sup.5R.sup.6 (n represents an integer of 0 to 2, R.sup.3 represents a perfluoropolyether chain, R.sup.4, R.sup.2, and R.sup.5 represent a divalent linking group having one or more polar groups, R.sup.2 and R.sup.5 have an oxygen atom at an end bonded to R.sup.1 or R.sup.6, R.sup.1 and R.sup.6 represent an organic group having 1 to 50 carbon atoms or a hydrogen atom, at least one of R.sup.1 or R.sup.6 is represented by Formula (2), one of X and Y represents CO, and the other represents NH, NR.sup.7 (R.sup.7 represents a hydrocarbon group having 1 to 8 carbon atoms), or O, Q represents a 5- to 8-membered heterocyclic ring structure, which is formed of a carbon atom of a linking group indicated by a dashed arc together with X and Y, and Z represents 0 to 5 substituents.)

##STR00001##