Polycyclic analogues of trans-decalones. Part 5. Synthesis, optical resolution and circular dichroism of trans-transoid-trans-perhydrophenanthren-3-one and trans-transoid-trans-perhydrophenanthren-9-one

Abstract

Racemic perhydrophenanthren-3-one and perhydrophenanthren-9-one have been synthesised from the tricyclic enones (±)-(3) and (±)-(12), respectively. The derived saturated equatorial hydroxy-compound (8a)(as well as its enantiomer) and (13a), resolved as their 3β-acetoxyandrost-5-ene-17β-carboxylates, afforded (+)-(4aS,4bS,8aR,10aS)-perhydrophenanthren-3-one (1)(and its enantiomer) and (–)-(4aS,4bR,8aS,10aR)-perhydrophenanthren-9-one (2), respectively, both of high optical purity. The c.d. data of compound (+)-(1) do not agree with previous empirical predictions and the consequences of this are discussed. The c.d. measurements for compound (–)-(2), which represents the simplest rigid ‘middle-ring’ ketone of the ‘all-trans’ perhydrophenanthrene class hitherto studied, clearly show that for such systems additivity of effects of individual rings does not hold.