Exaltone® (=Cyclopentadecanone) from Isomuscone® (=Cyclohexadecanone), a One-C-Atom Ring-Contraction Methodology via a Stereospecific Favorskii Rearrangement: Regioselective Application to (−)-(R)-Muscone
作者:Christian Chapuis、Fabrice Robvieux、Carole Cantatore、Christine Saint-Léger、Laurent Maggi
DOI:10.1002/hlca.201100398
日期:2012.3
Treatment of cyclohexadecanone (1g; with I2 (2.2 mol‐euqiv.) and KOH in MeOH) furnished the unsaturated (Z)‐ester 2g in 83% yield, via a stereospecific Favorskii rearrangement (Scheme 1). Further treatment with 3‐chloroperbenzoic acid (m‐CPBA) afforded the unreported epoxy ester 3g (88% yield), which was cleaved in 33% yield to Exaltone® (=cyclopentadecanone; 1f) with NaOH in MeOH/H2O and then HCl
环己癸酮(1g ;用I 2(2.2 mol-euqiv。)和KOH在MeOH中的溶液)的处理通过立体定向Favorskii重排提供了2%的不饱和(Z)-酯2g(方案1)。用3-氯过苯甲酸(进一步处理米-CPBA),得到未报告的环氧酯3克(88%产率),将其在33%产率,以裂解Exaltone ®(=环十五; 1F)用NaOH在MeOH / H 2 O和然后HCl在65°。该方法类似地扩展到较高的温度(C 17)和较低的温度(C 15C 11)的环状酮类似物,以及对(-)-(R)-muscone(5c)和homomuscone(5f)的区域选择性(方案2)。相应的大环-1-氧杂螺的嗅觉特性[2,Ñ ]烷烃和烯烃4和8,从所得到的科里 Chaykovsky oxiranylation,还提出。