Process for the preparation of 20-keto-21 alpha-01-steroids
US5399685A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 11, 1993 |
| Grant date | Mar 21, 1995 |
| Priority date | — |
| Expiry date | Jun 11, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07J41/0094
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for the preparation of a compound of the formula ##STR1## wherein R.sub.1 is alkyl of 1 to 3 carbon atoms, R.sub.2 is alkyl of 1 to 12 carbon atoms, R.sub.3 is alkyl of 1 to 4 carbon atoms comprising reacting a compound of the formula ##STR2## wherein R.sub.4 is a remainder of an easily cleavable ether, K is a protected ketone function in the form of ketal, thioketal or mixed ketal and R.sub.1 has the above definition with a magnesium organic compound reagent of the formula EQU HalMg--CH.sub.2 --R.sub.2 A wherein Hal is a halogen and R.sub.2 is defined as above to obtain a compound of the formula ##STR3## wherein R.sub.1, R.sub.2 and K are defined as above, reacting the latter with an acylation agent to obtain a compound of the formula ##STR4## wherein R.sub.5 is alkyl of 1 to 6 carbon atoms or aryl of 6 to 10 carbon atoms and R.sub.1, R.sub.2 and K are defined as above, reacting the latter with an appropriate alkylation agent to obtain a compound of the formula ##STR5## wherein R.sub.1, R.sub.2, R.sub.3 and K are defined as above, subjecting the latter to autoxidation to obtain a compound of the formula ##STR6## wherein R.sub.1, R.sub.2, R.sub.3 and K are defined as abov…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.