Steroide und Sexualhormone 256. Mitteilung 1. Quassinoide Bitterstoffe I 1‐Oxo‐2‐methoxy‐4α‐methyl‐17β‐hydroxy‐Δ2‐5α‐androsten als Modell für den Ring A des Quassins

Starting from 3‐oxo‐17β‐hydroxy‐Δ1‐5α‐androstene (2b) the preparation of 1‐oxo‐2‐methoxy‐4α‐methyl‐17β‐hydroxy‐Δ2‐5α‐androstene (9), a compound with the ring A structure of quassine (1) is described. The key problem of the reaction sequence is shown to be the monomethylation at C(4).