Olsen, Sigurd; Bredoch, Ragnar published the artcile< Oxygen containing ring systems. The synthesis of oxacycloheptan-4-one and 4,4'-oxido-4-methyltetrahydropyran>, SDS of cas: 112-63-0, the main research area is .
MeCH(OAc)-(CH2)2OAc distilled at atm. pressure with p-MeC6H4SO3H.H2O and the crude distillate treated with concentrated H2SO4 and glacial AcOH and paraformaldehyde yielded 4-acetoxytetrahydropyran (I), b9 71.5, n20D 1.4413, d20 1.0692, MRD 35.62. I (269 g.) transesterified with MeOH-HCl yielded 188 g. 4-OH analog (II) of I, b13 88.5°, n20D 1.461, d20 1.0649, MRD 26.20; p-nitrobenzoate, m. 69-71° (petr. ether); phenylurethan, 97-9° (ligroine); α-naphthylurethan, m. 130-2° (ligroine). II (96 g.) in 375 cc. H2O treated with cooling and stirring during 0.5 hr. with 120 g. Na2Cr2O7, 125 cc. H2O, and 176 cc. concentrated H2SO4, allowed to stand 15 hrs., neutralized with solid Na2CO3, extracted with 3.5 l. Et2O, and the extract worked up gave 8.5 g. unchanged II and 49 g. 4-oxotetrahydropyran (III), b11 57-9°, n20D 1.451, d20 1.0825, MRD 24.92; 2,4-dinitrophenylhydrazone, m. 186-8°; phenylsemicarbazone, m. 170-1°. III (25 g.) in 190 cc. MeOH treated at room temperature during 15 min. in 2 portions with 10% excess CH2N2 in Et2O, kept 15 hrs., and worked up gave 22.8% 4,4′-oxido-4-methyltetrahydropyran (IV), b8 44-5°, n20D 1.450, d20 1.055, MRD 29.08, and 60% oxacycloheptan-4-one (V), b8 68°, n20D 1.4611, d20 1.0682, MRD 29.33, decomposed by boiling with 2N HCl; phenylsemicarbazone, m. 168-9° (EtOH); 2,4-dinitrophenylhydrazone, m. 173-4° (MeOH). V (3 g.) in 20 cc. H2O treated with 16.7 g. KMnO4 in 500 cc. H2O and 1 cc. 30% aqueous NaOH, warmed on the water bath, filtered, treated with 5 cc. concentrated HCl, evaporated, and the residue extracted 2.5 hrs. with Et2O gave 1.6 g. (CH2CO2H)2, m. 184-6°. V (35 g.) added dropwise with stirring during 20 min. to 4.3 g. LiAlH4 in 175 cc. dry Et2O, refluxed 1 hr., decomposed with dilute H2SO4, and worked up in the usual manner gave 31.5 g. oxacycloheptan-4-ol (VI), b8 84-6° n22D 1.471, d22 1.0595, MRD) 30.64. V (12 g.) in 170 cc. MeOH hydrogenated 26 hrs. over 870 mg. PtO2, filtered, and distilled gave 10 g. VI; phenylurethan, m. 84-6° (ligroine); α-naphthylurethan, m. 119-21° (ligroine). VI (61 g.) and 75 cc. Ac2O refluxed 2 hrs. with a few drops concentrated H2SO4, diluted with H2O and aqueous NaHCO3, extracted with Et2O, and the extract worked up gave 52 g. acetate (VII) of VI, b9 86° n20D 1.450, d20 1.0595, MRD 40.13. VII (64 g.) heated 3.5 hrs. with 4.5 g. p-MeC6H4SO3H at 300-25°, the distillate (45 g.), b. 75-96° basified with aqueous Na2CO3 and extracted with Et2O, and the extract distilled gave 27.5 g. oxa-3-cycloheptene (VIII), b760 98-100°, n20D 1.4562, d20 0.9266, MRD 28.80. VIII (1 g.) added dropwise with stirring to 8.6 g. KMnO4 and 2 g. Na2CO3 in 250 cc. H2O at 60°, heated 2 hrs. on the water bath, filtered, acidified, evaporated, and the residue extracted 5 hrs. with Et2O yielded 1 g. acid mixture which chromatographed gave (CH2CO2H)2. VIII (11 g.) in 210 cc. MeOH hydrogenated 15 min. over 0.782 g. gave 3.5 g. oxacycloheptane (IX), b. 119.5°, n19.5D 1.4358, d19.5 0.8875, MRD 29.49. IX (0.3 cc.) and 4 cc. 66% HBr heated 18 hrs. at 105°, extracted with Et2O, and the extract worked up gave 0.7 g. Br(CH2)6Br (X). X (0.7 g.) refluxed with excess PhONa in EtOH 15 min., filtered, and cooled gave [(CH2)3OPh]2, m. 83-5°. IV (16 g.) and 0.25 g. ZnCl2 distilled at 240-340° gave 11 g. distillate, b. 110-67°, which contained unchanged IV and 4-formyltetrahydropyran (XI); 2,4-dinitrophenylhydrazone, m. 166-8° (MeOH); semicarbazone, 194-6° (H2O). A portion of the distillate kept several days in a stoppered container gave dimeric XI, m. 218-23° (MeOH); another portion of the distillate kept under O during several days, the resulting crystalline material treated with H2O, and the insoluble portion filtered off gave dimeric XI; the filtrate evaporated yielded tetrahydropyran-4-carboxylic acid, m. 88-90°. VIII (14 g.) distilled during 5 hrs. under a weak air stream over 10% Pd-asbestos at 350° and the effluent condensed in a liquid air trap yielded 12.5 g. mainly unchanged VIII and about 0.5 cc. H2O. The infrared absorption spectra of tetrahydro-γ-pyrone, Δ3-dihydropyran, II, V, VI, and VIII are recorded.
Chemische Berichte published new progress about Blood pressure. 112-63-0 belongs to class esters-buliding-blocks, and the molecular formula is C19H34O2, SDS of cas: 112-63-0.
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