4-methoxyphenyl propanol, oxidation

Sinha et al. [7] for the first time reported a highly efficient and recyclable combination of Candida antarctica lipase B (CAL-B) and nentral ionic liqnid [hmim] [Br] for metal-free activation in the chemoselective oxidation of aryl alcohols. Initial study was carried out using 4-methoxyphenyl propanol, as substrate, and HjOj at 40°C in the presence of CAL-B/[hmim][Br], thereby providing aldehyde in 90% yield after 16 h. Increasing the reaction temperature to 60°C significantly brought down the reaction time from 16 to 8 h (Scheme 14.7). 

Preparation by oxidation of l-(3-chloro-2-methoxyphenyl)-l-propanol with chromium ttioxide in the presence of dilute sulfuric acid in acetone [6477],... 

Also obtained by reaction of propionyl chloride (SM) with guaiacol in carbon disulfide in the presence of aluminium chloride for 1 h at 70° (70%) [6671]. SM was formed in situ by action of oxalyl chloride with sodium propionate (method B). Also obtained by oxidation of l-(4-hydroxy-3-methoxyphenyl)-l-propanol (m.p. 69°) [7168],... 

Preparation by oxidation of (3,5-dimethoxy-4-hydroxy-phenyl)ethylcarbinolalsonamedl-(4-hyd-roxy-3,5-di-methoxyphenyl)-1 -propanol. 

---