Patent GB-667131-A (GB)
Title: Process for the manufacture of heterocyclic-substituted carbinols
IPC: C07D309/26
Filed: 1949-08-12
Abstract: Heterocyclic substituted carbinols of the formula <FORM:0667131/IV (a)/1> where X is an unsubstituted or a hydrocarbon substituted dihydropyranyl radical, R is hydrogen or a hydrocarbon group and Y is a heterocyclic group of the formula <FORM:0667131/IV (a)/2> which may also contain one or more nuclear hydrocarbon substituents and where Z is CH=O or C=O (hydrocarbon) are used as resin formers for the preparation of resins and other high molecular weight polymers.  The compounds may be polymerized in the presence of acid with polyhydric alcohols such as glycols, glycerol and sugar alcohols to form resinous and sub-resinous polymers which in the fully hardened, i.e. cross-linked state may be employed for manufacturing purposes such as films for decorative and protective coatings.  A preferred compound for this purpose is 2-(2 - formyl - 3 : 4 - dihydro - 1 : 2 - pyranyl)-2-(3 : 4-dihydro-1 : 2-pyranyl)-carbinol.ALSO:A process for the manufacture of heterocyclic-substituted carbinols represented by the formula <FORM:0667131/IV (b)/1> wherein X is an unsubstituted or a hydrocarbon-substituted dihydropyranyl radical, Y is a heterocyclic group <FORM:0667131/IV (b)/2> wherein Z stands for <FORM:0667131/IV (b)/3> hydrocarbon or Y represents a heterocyclic group of the formula given containing one or more nuclear hydrocarbon substituents, and R is a hydrogen atom or a hydrocarbon group, comprises condensing one or more acyl-substituted dihydropyrans which contain an aryl group at the carbon atom in the 2-position of the dihydropyran ring in the presence of water and of a basic condensation catalyst.  The formyl or keto group of the resulting aldehydeor keto-carbinol may be hydrogenated to a carbinol group. The radicals R and Z will be the same or different depending on whether only one or more than one aryl-substituted dihydropyrans is or are condensed.  Catalysts mentioned are alkali metal hydroxides and carbonates, alkaline earth metal hydroxides, sodium acetate, bicarbonate, or borate and trisodium phosphate and citrate, generally in concentrations of 0.005 to 5 gm.-equivalents per litre of aqueous solution.  Amounts of water between about 1 mole and about 100 moles per mole of acyl-substituted dihydropyran are suitable.  Reaction temperatures between about 0 DEG  and 75 DEG  C. are mentioned. Preferred starting materials are the 2-acyl-3,4-dihydro-1,2-pyrans and their 5- and/or 6-hydrocarbyl substitution products.  Hydrocarbyl substituents specified are methyl, ethyl, propyl, isopropyl, amyl, hexyl, octyl, lauryl, octadecyl, cyclopropyl, cyclohexyl, vinyl, allyl, crotyl, phenyl, ethynyl, cyclopentenyl, styryl, phenethyl, acenaphthenyl, fenchyl, menthyl, carvacryl, chaulmoogryl, cyclohexadienyl.  In examples: (1) 2-(2-formyl-3,4-dihydro-1,2-pyranyl) - 2 - (3,4 - dihydro - 1,2 - pyranyl) carbinol is obtained by condensing 2-formyl-3,4 - dihydro - 1,2 - pyran in aqueous sodium hydroxide solution.  The product may be hydrogenated to 2-(2-methyloltetrahydropyranyl) - 2 - tetrahydro - pyranyl carbinol; (2) 2 - (2 - acetyl - 6 - methyl - 3,4 - dihydro - 1,2-pyranyl) - 2,6 - methyl - 3,4 - dihydro - 1,2-pyranyl) methyl carbinol is obtained by condensing 2 - acetyl - 6 - methyl - 3,4 - dihydro-1,2-pyran in aqueous potassium hydroxide solution.  A list of products shows compounds similar to that obtained by (1) having methyl or ethyl substituents at one or more of the 5 and 6 positions of the pyran nuclei, and products similar to those obtained in (2) having 6-methyl substituents in one or both pyranyl nuclei or having a 2-propionyl in place of the 2-acetyl group.  Products mentioned having a carbinol group at Z in the above formula are: 2 - (2 - methylol - 3,4 - dihydro - 1,2 - pyranyl)-2 - (3,4 - dihydro - 1,2 - pyranyl) - carbinol, and its 5- and/or 6-methyl, or 6-ethyl derivatives, and 2-(2-methylmethylol-3,4-dihydro-1,2 - pyranyl) - 2 - (3,4 - dihydro - 1,2 - pyranyl) methyl carbinol having methyl and/or propyl substituents at the 5- and/or 6-positions.  The product of (2) by reaction with water in the presence of acid and catalytically activated hydrogen yields polyhydric alcohols, e.g. 5-methylol - 1,5,6,7,11 - hendecanepentol and 7-methylol-1,5,6,11-hendecanetetral which may be converted to esters with drying oil acids for use in paint and varnish. 2-(2-Acetyl-3,4 - dihydro - 1,2 - pyranyl) - 2 - (3,4 - dihydro-1,2 - pyranyl) - carbinol and its substitution derivatives may be halogenated to produce saturated halogen-containing derivatives for use as insecticides or converted to oximes.  The dihydric carbinols obtained by reduction of the initial condensation products may be further hydrogenated to saturate the olefinic bonds and may then be esterified to give softening agents.  The acyl-substituted dihydropyrans used as starting materials may be prepared by heating one or more a ,b -olefinic aldehydes or ketones in the liquid state, e.g. at 150 DEG  to 250 DEG C. in the presence of a polymerization inhibitor or by ring-closure of aliphatic-substituted aldehydes or ketones.