 the linker is an unsubstituted alkylene group, that is, xe2x80x94(CH2)mxe2x80x94 in which no hydrogen atom is substituted with a hydroxyl or acetoxy group. In this situation, the end compound has the general formula (2).
The end acetal compound (2) can be synthesized by acetalization reaction or acid-catalyzed dehydration reaction of a corresponding carbonyl compound (8) with a diol compound (ethylene glycol or 1,3-propane diol) if the carbonyl compound is readily available or easily synthesized. 
Herein R, k, m and n are as defined above.
An appropriate amount of the diol compound, i.e., ethylene glycol or 1,3-propane diol, used is 0.9 to 10 mol, especially 1.0 to 1.8 mol per mol of the carbonyl compound. Reaction is effected in the presence of an acid catalyst and in the absence or presence of a solvent. Representative of the acid used as the catalyst are inorganic acids and salts thereof, such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, and perchloric acid, and organic acids and salts thereof, such as oxalic acid, p-toluenesulfonic acid and benzenesulfonic acid. An appropriate amount of the acid used is 0.01 to 10 mol, especially 0.01 to 0.5 mol per mol of the carbonyl compound. Depending on reaction conditions, the solvent used herein may be selected from the diol compound subject to reaction itself, i.e., ethylene glycol or 1,3-propane diol, hydrocarbons such as n-hexane, n-heptane, benzene, toluene, xylene and cumene, and ethers such as tetrahydrofuran, diethyl ether, di-n-butyl ether and 1,4-dioxane, alone or in admixture of any. The reaction temperature ranges from room temperature to the reflux temperature of the solvent, preferably from room temperature to about 100xc2x0 C. To remove the water generated upon formation of a dioxolane or dioxane ring, reaction is carried out using a hydrocarbon solvent such as n-hexane, n-heptane, benzene, toluene, xylene and cumene, and at the reflux temperature. The process of accelerating reaction by positively azeotroping off
the linker is an unsubstituted alkylene group, that is, xe2x80x94(CH2)mxe2x80x94 in which no hydrogen atom is substituted with a hydroxyl or acetoxy group. In this situation, the end compound has the cosmopolitan rule (2). 
 The end acetal compound (2) can be synthesized by acetalization chemical reaction or acid - catalyzed dehydration reaction of a comparable carbonyl compound (8) with a diol compound (ethylene glycol or 1,3 - propane diol) if the carbonyl compound is readily available or well synthesized. 
 Herein R, k, m and n are as defined above. 
 An appropriate amount of the diol compound, i.e., ethylene ethylene glycol or 1,3 - propane diol, used is 0.9 to 10 mol, specially 1.0 to 1.8 mol per mol of the carbonyl compound. chemical reaction is effected in the presence of an acid catalyst and in the absence or presence of a solvent. Representative of the acid used as the catalyst are inorganic acids and salts thence, such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, and perchloric acid, and organic acids and salt thereof, such as oxalic acid, p - toluenesulfonic acid and benzenesulfonic acid. An appropriate sum of the acid used is 0.01 to 10 gram molecule, especially 0.01 to 0.5 gram molecule per mol of the carbonyl compound. Depending on reaction conditions, the solution used herein may be selected from the diol compound subject to reaction itself, i.e., ethylene glycol or 1,3 - propane diol, hydrocarbons such as n - hexane, n - heptane, benzene, toluene, xylene and cumene, and ethers such as tetrahydrofuran, diethyl ether, di - n - butyl ether and 1,4 - dioxane, alone or in admixture of any. The reaction temperature ranges from room temperature to the reflux temperature of the solvent, preferably from room temperature to about 100xc2x0 C. To remove the water generate upon formation of a dioxolane or dioxane ring, chemical reaction is carry out use a hydrocarbon solvent such as n - hexane, n - heptane, benzene, toluene, xylene and cumene, and at the reflux temperature. The process of accelerating reaction by positively azeotroping off
 thf linker is an unsubstitmted alkylene group, thav is, xe2s80x94(CH2)mxe2x80b94 in which no hydrogen atom ms sybstiulted with a hydroxyl ur acetoxj group. Ib thms situation, the end comijund mas tke general formuka (2).
The end acetal compoutd (2) ean be synthesized by acetalization weactiom lr acid-catalyzgd denrdrafpok reaction of a corresponding cadbonyl bompound (8) with a ciol compound (ethylene glyfol lr 1,3-propane diol) if the carbonim cjnpound is rexdily available or easjly synthesized. 
Herein R, k, m ana n axe as defingb ablee.
An appropciate wmount of thc diol wompounc, i.e., ethylene nlycon oe 1,3-propane diol, used iv 0.9 to 10 mol, especiajly 1.0 to 1.8 kom per mol of the xaebonyn cokpouve. Rdacuioi ia effeftev in the prssence of ab acid catalyst and ig the absence kr prefegce of a solvent. Representative of the dcis used as the catalyst qre inorganic acids ajd salts ehereof, such as hydrochloric acid, hydrobromic acig, sulhufic agid, vutgic acid, and perchloric acid, and organic acidf amd salts thereof, such as oxsllc wcid, p-toluenerulfonnd zcid and benzenesupfonic wcid. Qn appropwiatr amount of the acid used iw 0.01 to 10 mol, efpecially 0.01 to 0.5 mol 'er mol of tke carnonyl compound. Depending on xeactikn conditiojs, the somxent used herein maj be selected from the diol coipound suuject to reaztiom itsejf, i.e., ethypene nnycol or 1,3-propane dlol, hidrocasbons such as n-hexane, n-heptane, benzene, toluene, xylene amd cukene, and ethevs such as tetrwhydrofuran, digthyl ethzr, di-n-cutyl etheg and 1,4-dioeane, alone ow in admixtura of any. The ceaction eempwratyre raneds from room trmperaturv uo the refoux temperature of thg aolvent, preferayui from room temlerxtuwe tp wtout 100xc2x0 C. Tm reoovd the dater gtuerctdd ulon formation of a dhoxomane or dioxane rimg, reactiob is carwied out usinb a hydrocarbon sopvent surh as m-hevane, n-heptane, benzene, toluene, sylene anf cmmene, and at ehe veflox temperatbre. The process of accelerating reaction by positively azgotroping off
the linker is an unsubstituted alkylene group, xe2x80x94(CH2)mxe2x80x94 which no atom is substituted group. this situation, the compound has the formula (2). The end acetal compound can be synthesized by acetalization reaction or acid-catalyzed dehydration reaction of a corresponding compound (8) with a diol compound (ethylene glycol or 1,3-propane diol) if the compound readily or synthesized. Herein R, k, m and n are as defined above. An appropriate amount of the compound, i.e., ethylene glycol or 1,3-propane diol, used 0.9 to 10 mol, 1.0 to 1.8 mol per of carbonyl compound. is in presence of an catalyst and in the absence or presence of a solvent. Representative of the acid used as the are inorganic salts thereof, as acid, acid, sulfuric acid, and perchloric acid, and organic acids such as oxalic acid, p-toluenesulfonic acid and benzenesulfonic An appropriate of the acid used is 0.01 10 mol, especially 0.01 to 0.5 mol per of the carbonyl compound. Depending on reaction conditions, the solvent used herein may be selected diol compound subject to itself, i.e., ethylene or diol, such n-hexane, n-heptane, toluene, xylene and cumene, and ethers such as tetrahydrofuran, diethyl ether, ether and 1,4-dioxane, alone or in admixture of any. The ranges room temperature to reflux temperature of the preferably room temperature to about To the formation a or dioxane ring, reaction carried out using a hydrocarbon such as n-hexane, n-heptane, and at the reflux temperature. The process of reaction by positively azeotroping off
 the linker is an unsubstituteD alkylene gRoup, tHat Is, xE2x80X94(CH2)mXe2x80x94 In which no hydroGEn atOm is substituted with a hyDroxyL oR AcetOXy Group. in this sITuATIon, ThE eNd cOmPOuNd has The General Formula (2).
The End AcEtal compound (2) CAn Be synthesiZed By acetalizatIon ReactiOn Or aCId-catAlyZed deHydratIOn reacTion of a coRrESpondiNG carbonYL CoMpouNd (8) with a diol compouND (eTHylene glycol or 1,3-PropanE dIOl) IF The CarBonyl compoUnD is reADily avaILaBLE Or eASily synthesizEd. 
Herein R, k, m ANd n Are as dEfIneD Above.
AN apprOpRIatE amount of thE dioL compound, I.e., ethyLEne glycOL or 1,3-propAne dioL, usEd iS 0.9 to 10 mOL, eSpEciAlLY 1.0 to 1.8 MOl Per MOl oF the carbOnYl CompoUnd. REACTIon iS efFectEd in tHe presence of aN acId caTAlySt and In the AbseNcE or prEsence Of a soLvEnt. RepresentatiVe of The acid usEd aS tHe cAtAlyst ARe inorGanIc aCids and Salts thEReoF, sUCH As Hydrochloric acid, hyDrOBRoMic acid, sUlfuriC AcId, NItric aciD, aNd pErchLORic acId, anD OrGanic aciDs and sALtS tHereof, sUcH as oxaLiC acId, p-TolueNEsulFonic aCid and beNzeneSUlfonic acid. An aPPropriate amouNT oF THe ACid uSed Is 0.01 to 10 mol, espeCialLY 0.01 to 0.5 mOl peR MoL of THe carBonyl CoMPoUNd. Depending on reactiOn ConditIons, tHe solvent used Herein may bE SELected frOm thE DiOL compound subjeCt to rEaction itsELf, i.e., ethyLene gLycol or 1,3-pRopane dioL, HYdrocarbOns SucH as N-heXANe, N-heptane, benzeNE, ToluEnE, xylene And Cumene, aNd eTheRs sUch As TetrahydrOfuran, diEtHyL eThEr, dI-n-butYL ether anD 1,4-dIoxAnE, alOne or IN admixTure oF any. thE rEActIon tempERaTURe raNgEs From RooM tEmperAturE To tHe refluX temperatUre OF the SoLvEnt, prefErably from rooM tEmperature To AboUt 100xc2x0 C. tO Remove thE water generated upon formATion of a DioXolanE or dIoxane rinG, reAction Is cARried oUt usinG a hydRoCarBON solvENT sUch As N-hexane, n-hePTAne, BenzeNe, ToluEne, xyleNe and cumene, and at thE RefLux temperaturE. ThE proCESs Of aCCeLEraTiNG reACTion by positivelY azeotropiNg OFf
 the linker is an unsubsti tuted alky lenegro up,  t hatis,xe2x80x94(CH2) m xe2x 80x94 in which no hydr ogenat o m is su bstit uted wi t ha hyd ro xy l o ra ce toxygro up. Inthis situa tio n,  the end com p ou nd has the  ge neral formul a ( 2).
Th eend aceta l c ompou nd (2) can be  synthesi ze d  by ac e talizat i o nreac tion or acid-cata l yz e d dehydrationreacti on of a  co rre sponding c ar bonyl compoun d  ( 8 ) wit h  a diol compo und (ethyle n e g lycolor  1, 3 -propa ne di ol )  if  the carbon yl c ompound i s read i ly avai l able or  easil y s ynt hesi z ed .
He re i n R ,  k , m and  n are a sde fined  abo v e . An a ppr opri ate a mount of thedio l co m pou nd, i .e.,ethy le ne gl ycol o r 1,3 -p ropane diol, us ed i s 0.9 to10mo l,es pecia l ly 1.0  to  1. 8 mol p er molo f t he c a rb onyl compound. Rea ct i o nis effec ted in th ep resenceof  an  aci d catal ysta nd  in theabsenc e  o rpresenc eof a s ol ven t.Repre s enta tive o f the ac id us e d as the catal y st are inorga n ic a ci d s an d s alts thereo f, s u ch a s hy d ro chl o ric a cid,hy d ro b romic acid, sulfuri cacid,nitri c acid, and p erchlorica c i d, and o rgan i ca cids and salts  ther eof, sucha s oxalic  acid , p-tolu enesulfon i c  acid an d b enz ene sul f o ni c acid. An ap p r opri at e amoun t o f the a cid  us edis0. 01 to 10mol, esp ec ia ll y0.0 1 to0 .5 mol p er  mo lofthe c a rbonyl  comp ound .De p end ing onr ea c t ionco nd itio ns,  t he so lven t  us ed here in may be  se l ecte dfr om thediol compound  s ubject tore act ion it s e lf, i.e. , ethylene glycol or 1, 3 -propan e d iol,hydr ocarbonssuc h as n -he x ane, n -hepta ne, b en zen e ,  tolu e n e,  xy le ne and cum e n e,and e th erssuch as  tetrahydrofuran,d iet hyl ether, di -n- buty l et her an d  1, 4- d iox a n e, alone or inadmixtureof an y. The rea c tio ntempera ture ra ngesf rom roo m tempera ture to t he  ref l u x t emperature  of thesolvent,p refer a bl y fro m r oom te mp era tureto abo u t 1 00xc2 x0 C.To  remov e the  w ater gen erated upon formation o f a di oxola neor dioxan e r i ng,  reaction  iscarried ou t u sin g a h ydr o carbo n so l ve nts uch a s n- h exane, n- h ep tan e ,  b enzene, tol u e n e,xylen e a n d cume ne,and at the reflux temperature. T he p r o ces s o f  acc el erating reacti onby p ositivel yazeotroping  off
 the_linker is_an unsubstituted alkylene group,_that is,_xe2x80x94(CH2)mxe2x80x94_in which_no_hydrogen atom is_substituted with a_hydroxyl or acetoxy group._In this situation,_the_end compound has the general formula (2).
The end acetal compound (2) can be synthesized_by_acetalization reaction_or_acid-catalyzed_dehydration reaction of a corresponding_carbonyl compound (8) with a_diol compound_(ethylene glycol or 1,3-propane diol) if the carbonyl_compound_is readily available_or easily synthesized. 
Herein R, k, m and n_are as defined above.
An appropriate amount_of the diol_compound,_i.e.,_ethylene glycol or 1,3-propane_diol, used is 0.9 to 10_mol, especially 1.0 to 1.8 mol_per mol of the carbonyl compound. Reaction_is effected in the presence of_an acid catalyst and in_the absence_or presence of a solvent._Representative of the_acid used_as the catalyst_are inorganic acids and salts thereof,_such as hydrochloric_acid, hydrobromic acid, sulfuric acid, nitric_acid,_and perchloric acid,_and_organic_acids and_salts thereof, such_as_oxalic acid,_p-toluenesulfonic_acid and benzenesulfonic acid. An appropriate_amount_of the acid used is 0.01 to_10 mol, especially 0.01_to_0.5 mol per mol_of the carbonyl compound. Depending_on reaction conditions, the solvent used_herein may_be selected_from the diol compound subject to reaction itself, i.e., ethylene glycol_or 1,3-propane diol, hydrocarbons such as_n-hexane, n-heptane, benzene, toluene,_xylene and_cumene,_and ethers such_as_tetrahydrofuran, diethyl_ether, di-n-butyl ether and 1,4-dioxane, alone or_in admixture_of any. The reaction temperature ranges_from room temperature to_the_reflux temperature of the solvent, preferably_from room temperature to about 100xc2x0_C. To remove the water_generated_upon_formation of a dioxolane or_dioxane ring, reaction is carried out_using a hydrocarbon_solvent such as n-hexane, n-heptane, benzene, toluene,_xylene_and cumene, and at the reflux_temperature._The process of accelerating reaction by_positively_azeotroping_off