http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-1023786-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_dc2f7134efa50484bb359fda73782848 |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07J71-00 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07J75-00 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07J7-00 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07J5-00 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07J5-00 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07J75-00 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07J71-00 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07J7-00 |
| filingDate | 1962-11-15-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1966-03-23-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-1023786-A |
| titleOfInvention | Process for the manufacture of cyclic hemi-acetals |
| abstract | The invention comprises (1) a process for the preparation of the 11,18-cyclohemiacetal of an 11b - hydroxy - 18 - oxo - pregnane compound wherein a 20-ketal of an 18,20-dioxo-pregnane compound which contains an 11a -hydroxy group, an 11a - or 11b -acyloxy group or an 11-keto group is treated in an anhydrous non-acidic organic solvent with a strong acid, in the 18-acetal so formed, if desired after reketalization of the liberated 20-oxo-group, the 11-oxygen function is converted by a known method into an 11b -hydroxyl group, and in the resulting compounds any ketal and acetal groups are split hydrogenolytically or by acid hydrolysis; and (2) 18-acetals of 3-oxygenated 18,20-dioxopregnanes and -isopregnanes containing an 11a -hydroxy group, an 11a - or 11b -acyloxy group or an oxo group, and their 20-ketals. Reketalization of the 20-oxo group in process (1) also generally yields an isopregnane in addition to the required pregnane. The last step of process (1) may be performed with a lower aliphatic carboxylic acid and a strong inorganic acid to give mixtures of the cyclohemiacetal and its acylate, which can be further acylated or hydrolysed. The starting materials may further contain free or functionally converted hydroxyl or oxo groups, alkyl groups or halogen atoms as substituents in the nucleus, the 17-side chain and the 10-methyl group; or they may be 19-nor compounds; and they may contain double bonds. Preferably they are D 4-3,18-dioxo-11-oxygenated - 20,20 - alkylenedioxy - pregnenes or their D 5-3-alkylene ketals. The 3-oxygen function in compounds (2) may be a free esterified or etherified hydroxyl group or a tree or ketalized oxo group. In examples: (1) 3,3:20,20 - bisethylenedioxy - 11b ,18 - dihydroxy - D 5 - pregnene is oxidized to 3,3:20,20 - bis-ethylenedioxy - 11,18 - dioxo - D 5 - pregnene, and this by the process of the invention is converted to 3,3:18,18 - bisethylenedioxy - 11,20 - dioxo -D 5-pregnene, this to a mixture of the diols epimeric in the 20-position and this to 3-oxo-11b ,18:18,20b - bisoxido - D 4 - pregnene and its 20a -epimer; (2) the dioxo starting material of (1) is converted by the process of the invention to the 3,3:18,18-bisethylenedioxy product of (1) and the corresponding 3,3:18,18:20,20-triethylenedioxy compound and the corresponding iso-pregnane, the second of these products to the corresponding 11b -ol and this to the (18,11b )-cyclohemiaceta of 3,18,20-trioxo-11b -hydroxy-D 4 - pregnene (21 - desoxyaldosterone), and the iso-compound to similar iso-pregnane products; and (3) the first product of (1) is prepared similarly and is hydrolysed in the same process to 3,11,30 - trioxo - 18,18 - ethylenedioxy - D 4 - pregnene. |
| priorityDate | 1961-11-17-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 30.