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Totalsynthese von (–)‐Norgestrel
Author(s) -
Baier Helmut,
Dürner Gerd,
Quinkert Gerhard
Publication year - 1985
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19850680430
Subject(s) - chemistry , intramolecular force , norgestrel , derivative (finance) , stereochemistry , acetophenone , stereospecificity , ether , medicinal chemistry , population , organic chemistry , catalysis , demography , sociology , family planning , financial economics , economics , research methodology
Total‐Synthesis of (–)‐Norgestrel (–)‐Norgestrel ( 1a ) or (–)‐norethindrone ( 1b ), two active progestational ingredients of currently used contraceptives have been synthesized stereoselectively. Compound 1a has been obtained starting from m ‐cresol methyl ether, dimethyl malonate, and ( E )‐1,4‐dibromo‐2‐butene. The steroid skeleton has been constructed using an intramolecular Diels ‐ Alder reaction of an o ‐quinodimethane derivative preceeded by a photo‐enolization of an appropriate methyl‐substituted acetophenone derivative. Chirality has been introduced at an early stage during an S cN ′ reaction (cf. Scheme 1) . Compound 1b has been obtained similarly using a previously reported mixture of the enantiomerically pure constitutional isomers 18b / 19b (cf. Scheme 3) .